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   <div class="section" id="module-apache_beam.transforms.core">
 <span id="apache-beam-transforms-core-module"></span><h1>apache_beam.transforms.core module<a class="headerlink" href="#module-apache_beam.transforms.core" title="Permalink to this headline">¶</a></h1>
 <p>Core PTransform subclasses, such as FlatMap, GroupByKey, and Map.</p>
 <dl class="class">
 <dt id="apache_beam.transforms.core.DoFn">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">DoFn</code><span class="sig-paren">(</span><em>*unused_args</em>, <em>**unused_kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.typehints.decorators.html#apache_beam.typehints.decorators.WithTypeHints" title="apache_beam.typehints.decorators.WithTypeHints"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.typehints.decorators.WithTypeHints</span></code></a>, <a class="reference internal" href="apache_beam.transforms.display.html#apache_beam.transforms.display.HasDisplayData" title="apache_beam.transforms.display.HasDisplayData"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.display.HasDisplayData</span></code></a>, <a class="reference internal" href="apache_beam.utils.urns.html#apache_beam.utils.urns.RunnerApiFn" title="apache_beam.utils.urns.RunnerApiFn"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.utils.urns.RunnerApiFn</span></code></a></p>
 <p>A function object used by a transform with custom processing.</p>
 <p>The ParDo transform is such a transform. The ParDo.apply
 method will take an object of type DoFn and apply it to all elements of a
 PCollection object.</p>
 <p>In order to have concrete DoFn objects one has to subclass from DoFn and
 define the desired behavior (start_bundle/finish_bundle and process) or wrap a
 callable object using the CallableWrapperDoFn class.</p>
 <dl class="attribute">
 <dt id="apache_beam.transforms.core.DoFn.ElementParam">
 <code class="descname">ElementParam</code><em class="property"> = 'ElementParam'</em><a class="headerlink" href="#apache_beam.transforms.core.DoFn.ElementParam" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="attribute">
 <dt id="apache_beam.transforms.core.DoFn.SideInputParam">
 <code class="descname">SideInputParam</code><em class="property"> = 'SideInputParam'</em><a class="headerlink" href="#apache_beam.transforms.core.DoFn.SideInputParam" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="attribute">
 <dt id="apache_beam.transforms.core.DoFn.TimestampParam">
 <code class="descname">TimestampParam</code><em class="property"> = 'TimestampParam'</em><a class="headerlink" href="#apache_beam.transforms.core.DoFn.TimestampParam" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="attribute">
 <dt id="apache_beam.transforms.core.DoFn.WindowParam">
 <code class="descname">WindowParam</code><em class="property"> = 'WindowParam'</em><a class="headerlink" href="#apache_beam.transforms.core.DoFn.WindowParam" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="attribute">
 <dt id="apache_beam.transforms.core.DoFn.WatermarkReporterParam">
 <code class="descname">WatermarkReporterParam</code><em class="property"> = 'WatermarkReporterParam'</em><a class="headerlink" href="#apache_beam.transforms.core.DoFn.WatermarkReporterParam" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="attribute">
 <dt id="apache_beam.transforms.core.DoFn.DoFnParams">
 <code class="descname">DoFnParams</code><em class="property"> = ['ElementParam', 'SideInputParam', 'TimestampParam', 'WindowParam']</em><a class="headerlink" href="#apache_beam.transforms.core.DoFn.DoFnParams" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.DoFn.from_callable">
 <em class="property">static </em><code class="descname">from_callable</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.from_callable"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.from_callable" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.default_label">
 <code class="descname">default_label</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.default_label"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.default_label" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.process">
 <code class="descname">process</code><span class="sig-paren">(</span><em>element</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.process"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.process" title="Permalink to this definition">¶</a></dt>
 <dd><p>Method to use for processing elements.</p>
 <p>This is invoked by <code class="docutils literal"><span class="pre">DoFnRunner</span></code> for each element of a input
 <code class="docutils literal"><span class="pre">PCollection</span></code>.</p>
 <p>If specified, following default arguments are used by the <code class="docutils literal"><span class="pre">DoFnRunner</span></code> to
 be able to pass the parameters correctly.</p>
 <p><code class="docutils literal"><span class="pre">DoFn.ElementParam</span></code>: element to be processed.
 <code class="docutils literal"><span class="pre">DoFn.SideInputParam</span></code>: a side input that may be used when processing.
 <code class="docutils literal"><span class="pre">DoFn.TimestampParam</span></code>: timestamp of the input element.
 <code class="docutils literal"><span class="pre">DoFn.WindowParam</span></code>: <code class="docutils literal"><span class="pre">Window</span></code> the input element belongs to.
 A <code class="docutils literal"><span class="pre">RestrictionProvider</span></code> instance: an <code class="docutils literal"><span class="pre">iobase.RestrictionTracker</span></code> will be
 provided here to allow treatment as a Splittable <cite>DoFn`</cite>.
 <code class="docutils literal"><span class="pre">DoFn.WatermarkReporterParam</span></code>: a function that can be used to report
 output watermark of Splittable <code class="docutils literal"><span class="pre">DoFn</span></code> implementations.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>element</strong> – The element to be processed</li>
 <li><strong>*args</strong> – side inputs</li>
 <li><strong>**kwargs</strong> – other keyword arguments.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.start_bundle">
 <code class="descname">start_bundle</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.start_bundle"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.start_bundle" title="Permalink to this definition">¶</a></dt>
 <dd><p>Called before a bundle of elements is processed on a worker.</p>
 <p>Elements to be processed are split into bundles and distributed
 to workers. Before a worker calls process() on the first element
 of its bundle, it calls this method.</p>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.finish_bundle">
 <code class="descname">finish_bundle</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.finish_bundle"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.finish_bundle" title="Permalink to this definition">¶</a></dt>
 <dd><p>Called after a bundle of elements is processed on a worker.</p>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.get_function_arguments">
 <code class="descname">get_function_arguments</code><span class="sig-paren">(</span><em>func</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.get_function_arguments"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.get_function_arguments" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.infer_output_type">
 <code class="descname">infer_output_type</code><span class="sig-paren">(</span><em>input_type</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.infer_output_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.infer_output_type" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.is_process_bounded">
 <code class="descname">is_process_bounded</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#DoFn.is_process_bounded"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.DoFn.is_process_bounded" title="Permalink to this definition">¶</a></dt>
 <dd><p>Checks if an object is a bound method on an instance.</p>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.DoFn.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="headerlink" href="#apache_beam.transforms.core.DoFn.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.CombineFn">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">CombineFn</code><span class="sig-paren">(</span><em>*unused_args</em>, <em>**unused_kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.typehints.decorators.html#apache_beam.typehints.decorators.WithTypeHints" title="apache_beam.typehints.decorators.WithTypeHints"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.typehints.decorators.WithTypeHints</span></code></a>, <a class="reference internal" href="apache_beam.transforms.display.html#apache_beam.transforms.display.HasDisplayData" title="apache_beam.transforms.display.HasDisplayData"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.display.HasDisplayData</span></code></a>, <a class="reference internal" href="apache_beam.utils.urns.html#apache_beam.utils.urns.RunnerApiFn" title="apache_beam.utils.urns.RunnerApiFn"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.utils.urns.RunnerApiFn</span></code></a></p>
 <p>A function object used by a Combine transform with custom processing.</p>
 <p>A CombineFn specifies how multiple values in all or part of a PCollection can
 be merged into a single value—essentially providing the same kind of
 information as the arguments to the Python “reduce” builtin (except for the
 input argument, which is an instance of CombineFnProcessContext). The
 combining process proceeds as follows:</p>
 <ol class="arabic simple">
 <li>Input values are partitioned into one or more batches.</li>
 <li>For each batch, the create_accumulator method is invoked to create a fresh
 initial “accumulator” value representing the combination of zero values.</li>
 <li>For each input value in the batch, the add_input method is invoked to
 combine more values with the accumulator for that batch.</li>
 <li>The merge_accumulators method is invoked to combine accumulators from
 separate batches into a single combined output accumulator value, once all
 of the accumulators have had all the input value in their batches added to
 them. This operation is invoked repeatedly, until there is only one
 accumulator value left.</li>
 <li>The extract_output operation is invoked on the final accumulator to get
 the output value.</li>
 </ol>
 <p>Note: If this <strong>CombineFn</strong> is used with a transform that has defaults,
 <strong>apply</strong> will be called with an empty list at expansion time to get the
 default value.</p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.default_label">
 <code class="descname">default_label</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.default_label"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.default_label" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.create_accumulator">
 <code class="descname">create_accumulator</code><span class="sig-paren">(</span><em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.create_accumulator"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.create_accumulator" title="Permalink to this definition">¶</a></dt>
 <dd><p>Return a fresh, empty accumulator for the combine operation.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>*args</strong> – Additional arguments and side inputs.</li>
 <li><strong>**kwargs</strong> – Additional arguments and side inputs.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.add_input">
 <code class="descname">add_input</code><span class="sig-paren">(</span><em>accumulator</em>, <em>element</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.add_input"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.add_input" title="Permalink to this definition">¶</a></dt>
 <dd><p>Return result of folding element into accumulator.</p>
 <p>CombineFn implementors must override add_input.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>accumulator</strong> – the current accumulator</li>
 <li><strong>element</strong> – the element to add</li>
 <li><strong>*args</strong> – Additional arguments and side inputs.</li>
 <li><strong>**kwargs</strong> – Additional arguments and side inputs.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.add_inputs">
 <code class="descname">add_inputs</code><span class="sig-paren">(</span><em>accumulator</em>, <em>elements</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.add_inputs"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.add_inputs" title="Permalink to this definition">¶</a></dt>
 <dd><p>Returns the result of folding each element in elements into accumulator.</p>
 <p>This is provided in case the implementation affords more efficient
 bulk addition of elements. The default implementation simply loops
 over the inputs invoking add_input for each one.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>accumulator</strong> – the current accumulator</li>
 <li><strong>elements</strong> – the elements to add</li>
 <li><strong>*args</strong> – Additional arguments and side inputs.</li>
 <li><strong>**kwargs</strong> – Additional arguments and side inputs.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.merge_accumulators">
 <code class="descname">merge_accumulators</code><span class="sig-paren">(</span><em>accumulators</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.merge_accumulators"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.merge_accumulators" title="Permalink to this definition">¶</a></dt>
 <dd><p>Returns the result of merging several accumulators
 to a single accumulator value.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>accumulators</strong> – the accumulators to merge</li>
 <li><strong>*args</strong> – Additional arguments and side inputs.</li>
 <li><strong>**kwargs</strong> – Additional arguments and side inputs.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.extract_output">
 <code class="descname">extract_output</code><span class="sig-paren">(</span><em>accumulator</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.extract_output"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.extract_output" title="Permalink to this definition">¶</a></dt>
 <dd><p>Return result of converting accumulator into the output value.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>accumulator</strong> – the final accumulator value computed by this CombineFn
 for the entire input key or PCollection.</li>
 <li><strong>*args</strong> – Additional arguments and side inputs.</li>
 <li><strong>**kwargs</strong> – Additional arguments and side inputs.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.apply">
 <code class="descname">apply</code><span class="sig-paren">(</span><em>elements</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.apply"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.apply" title="Permalink to this definition">¶</a></dt>
 <dd><p>Returns result of applying this CombineFn to the input values.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>elements</strong> – the set of values to combine.</li>
 <li><strong>*args</strong> – Additional arguments and side inputs.</li>
 <li><strong>**kwargs</strong> – Additional arguments and side inputs.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.for_input_type">
 <code class="descname">for_input_type</code><span class="sig-paren">(</span><em>input_type</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.for_input_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.for_input_type" title="Permalink to this definition">¶</a></dt>
 <dd><p>Returns a specialized implementation of self, if it exists.</p>
 <p>Otherwise, returns self.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>input_type</strong> – the type of input elements.</td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.CombineFn.from_callable">
 <em class="property">static </em><code class="descname">from_callable</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.from_callable"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.from_callable" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.CombineFn.maybe_from_callable">
 <em class="property">static </em><code class="descname">maybe_from_callable</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.maybe_from_callable"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.maybe_from_callable" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.get_accumulator_coder">
 <code class="descname">get_accumulator_coder</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineFn.get_accumulator_coder"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.get_accumulator_coder" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineFn.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="headerlink" href="#apache_beam.transforms.core.CombineFn.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.PartitionFn">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">PartitionFn</code><span class="sig-paren">(</span><em>*unused_args</em>, <em>**unused_kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#PartitionFn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.PartitionFn" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.typehints.decorators.html#apache_beam.typehints.decorators.WithTypeHints" title="apache_beam.typehints.decorators.WithTypeHints"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.typehints.decorators.WithTypeHints</span></code></a></p>
 <p>A function object used by a Partition transform.</p>
 <p>A PartitionFn specifies how individual values in a PCollection will be placed
 into separate partitions, indexed by an integer.</p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.PartitionFn.default_label">
 <code class="descname">default_label</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#PartitionFn.default_label"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.PartitionFn.default_label" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.PartitionFn.partition_for">
 <code class="descname">partition_for</code><span class="sig-paren">(</span><em>element</em>, <em>num_partitions</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#PartitionFn.partition_for"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.PartitionFn.partition_for" title="Permalink to this definition">¶</a></dt>
 <dd><p>Specify which partition will receive this element.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>element</strong> – An element of the input PCollection.</li>
 <li><strong>num_partitions</strong> – Number of partitions, i.e., output PCollections.</li>
 <li><strong>*args</strong> – optional parameters and side inputs.</li>
 <li><strong>**kwargs</strong> – optional parameters and side inputs.</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first last">An integer in [0, num_partitions).</p>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.ParDo">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">ParDo</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransformWithSideInputs</span></code></p>
 <p>A <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a> transform.</p>
 <p>Processes an input <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> by applying a
 <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> to each element and returning the accumulated results into an
 output <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a>. The type of the elements is
 not fixed as long as the <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> can deal with it. In reality the type
 is restrained to some extent because the elements sometimes must be persisted
 to external storage. See the <a class="reference internal" href="#apache_beam.transforms.core.ParDo.expand" title="apache_beam.transforms.core.ParDo.expand"><code class="xref py py-meth docutils literal"><span class="pre">expand()</span></code></a> method comments for a
 detailed description of all possible arguments.</p>
 <p>Note that the <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> must return an iterable for each element of the
 input <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a>. An easy way to do this is to
 use the <code class="docutils literal"><span class="pre">yield</span></code> keyword in the process method.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>pcoll</strong> (<a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><em>PCollection</em></a>) – a <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> to be processed.</li>
 <li><strong>fn</strong> (<a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><em>DoFn</em></a>) – a <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> object to be applied to each element
 of <strong>pcoll</strong> argument.</li>
 <li><strong>*args</strong> – positional arguments passed to the <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> object.</li>
 <li><strong>**kwargs</strong> – keyword arguments passed to the <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> object.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 <p>Note that the positional and keyword arguments will be processed in order
 to detect <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> s that will be computed as
 side inputs to the transform. During pipeline execution whenever the
 <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> object gets executed (its <a class="reference internal" href="#apache_beam.transforms.core.DoFn.process" title="apache_beam.transforms.core.DoFn.process"><code class="xref py py-meth docutils literal"><span class="pre">DoFn.process()</span></code></a> method gets
 called) the <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> arguments will be
 replaced by values from the <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> in the
 exact positions where they appear in the argument lists.</p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.default_type_hints">
 <code class="descname">default_type_hints</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.default_type_hints"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.default_type_hints" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.infer_output_type">
 <code class="descname">infer_output_type</code><span class="sig-paren">(</span><em>input_type</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.infer_output_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.infer_output_type" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.make_fn">
 <code class="descname">make_fn</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.make_fn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.make_fn" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.display_data">
 <code class="descname">display_data</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.display_data"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.display_data" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.with_outputs">
 <code class="descname">with_outputs</code><span class="sig-paren">(</span><em>*tags</em>, <em>**main_kw</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.with_outputs"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.with_outputs" title="Permalink to this definition">¶</a></dt>
 <dd><p>Returns a tagged tuple allowing access to the outputs of a
 <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a>.</p>
 <p>The resulting object supports access to the
 <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> associated with a tag
 (e.g. <code class="docutils literal"><span class="pre">o.tag</span></code>, <code class="docutils literal"><span class="pre">o[tag]</span></code>) and iterating over the available tags
 (e.g. <code class="docutils literal"><span class="pre">for</span> <span class="pre">tag</span> <span class="pre">in</span> <span class="pre">o:</span> <span class="pre">...</span></code>).</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>*tags</strong> – if non-empty, list of valid tags. If a list of valid tags is given,
 it will be an error to use an undeclared tag later in the pipeline.</li>
 <li><strong>**main_kw</strong> – dictionary empty or with one key <code class="docutils literal"><span class="pre">'main'</span></code> defining the tag to
 be used for the main output (which will not have a tag associated with
 it).</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">An object of type
 <code class="xref py py-class docutils literal"><span class="pre">DoOutputsTuple</span></code> that bundles together all
 the outputs of a <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a> transform and allows accessing the
 individual <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> s for each output
 using an <code class="docutils literal"><span class="pre">object.tag</span></code> syntax.</p>
 </td>
 </tr>
 <tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first">DoOutputsTuple</p>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><ul class="first last simple">
 <li><a class="reference external" href="https://docs.python.org/2/library/exceptions.html#exceptions.TypeError" title="(in Python v2.7)"><code class="xref py py-exc docutils literal"><span class="pre">TypeError</span></code></a> – if the <strong>self</strong> object is not a
 <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> that is the result of a
 <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a> transform.</li>
 <li><a class="reference external" href="https://docs.python.org/2/library/exceptions.html#exceptions.ValueError" title="(in Python v2.7)"><code class="xref py py-exc docutils literal"><span class="pre">ValueError</span></code></a> – if <strong>main_kw</strong> contains any key other than
 <code class="docutils literal"><span class="pre">'main'</span></code>.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.ParDo.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.ParDo.from_runner_api_parameter">
 <em class="property">static </em><code class="descname">from_runner_api_parameter</code><span class="sig-paren">(</span><em>pardo_payload</em>, <em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#ParDo.from_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.ParDo.from_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="function">
 <dt id="apache_beam.transforms.core.FlatMap">
 <code class="descclassname">apache_beam.transforms.core.</code><code class="descname">FlatMap</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#FlatMap"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.FlatMap" title="Permalink to this definition">¶</a></dt>
 <dd><p><a class="reference internal" href="#apache_beam.transforms.core.FlatMap" title="apache_beam.transforms.core.FlatMap"><code class="xref py py-func docutils literal"><span class="pre">FlatMap()</span></code></a> is like <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a> except it takes a callable to
 specify the transformation.</p>
 <p>The callable must return an iterable for each element of the input
 <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a>. The elements of these iterables will
 be flattened into the output <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a>.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>fn</strong> (<a class="reference external" href="https://docs.python.org/2/library/functions.html#callable" title="(in Python v2.7)"><em>callable</em></a>) – a callable object.</li>
 <li><strong>*args</strong> – positional arguments passed to the transform callable.</li>
 <li><strong>**kwargs</strong> – keyword arguments passed to the transform callable.</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">A <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> containing the
 <a class="reference internal" href="#apache_beam.transforms.core.FlatMap" title="apache_beam.transforms.core.FlatMap"><code class="xref py py-func docutils literal"><span class="pre">FlatMap()</span></code></a> outputs.</p>
 </td>
 </tr>
 <tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection">PCollection</a></p>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><p class="first last"><a class="reference external" href="https://docs.python.org/2/library/exceptions.html#exceptions.TypeError" title="(in Python v2.7)"><code class="xref py py-exc docutils literal"><span class="pre">TypeError</span></code></a> – If the <strong>fn</strong> passed as argument is not a callable.
 Typical error is to pass a <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> instance which is supported only
 for <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a>.</p>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="function">
 <dt id="apache_beam.transforms.core.Map">
 <code class="descclassname">apache_beam.transforms.core.</code><code class="descname">Map</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Map"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Map" title="Permalink to this definition">¶</a></dt>
 <dd><p><a class="reference internal" href="#apache_beam.transforms.core.Map" title="apache_beam.transforms.core.Map"><code class="xref py py-func docutils literal"><span class="pre">Map()</span></code></a> is like <a class="reference internal" href="#apache_beam.transforms.core.FlatMap" title="apache_beam.transforms.core.FlatMap"><code class="xref py py-func docutils literal"><span class="pre">FlatMap()</span></code></a> except its callable returns only a
 single element.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>fn</strong> (<a class="reference external" href="https://docs.python.org/2/library/functions.html#callable" title="(in Python v2.7)"><em>callable</em></a>) – a callable object.</li>
 <li><strong>*args</strong> – positional arguments passed to the transform callable.</li>
 <li><strong>**kwargs</strong> – keyword arguments passed to the transform callable.</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">A <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> containing the
 <a class="reference internal" href="#apache_beam.transforms.core.Map" title="apache_beam.transforms.core.Map"><code class="xref py py-func docutils literal"><span class="pre">Map()</span></code></a> outputs.</p>
 </td>
 </tr>
 <tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection">PCollection</a></p>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><p class="first last"><a class="reference external" href="https://docs.python.org/2/library/exceptions.html#exceptions.TypeError" title="(in Python v2.7)"><code class="xref py py-exc docutils literal"><span class="pre">TypeError</span></code></a> – If the <strong>fn</strong> passed as argument is not a callable.
 Typical error is to pass a <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> instance which is supported only
 for <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a>.</p>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="function">
 <dt id="apache_beam.transforms.core.Filter">
 <code class="descclassname">apache_beam.transforms.core.</code><code class="descname">Filter</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Filter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Filter" title="Permalink to this definition">¶</a></dt>
 <dd><p><a class="reference internal" href="#apache_beam.transforms.core.Filter" title="apache_beam.transforms.core.Filter"><code class="xref py py-func docutils literal"><span class="pre">Filter()</span></code></a> is a <a class="reference internal" href="#apache_beam.transforms.core.FlatMap" title="apache_beam.transforms.core.FlatMap"><code class="xref py py-func docutils literal"><span class="pre">FlatMap()</span></code></a> with its callable filtering out
 elements.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>fn</strong> (<a class="reference external" href="https://docs.python.org/2/library/functions.html#callable" title="(in Python v2.7)"><em>callable</em></a>) – a callable object.</li>
 <li><strong>*args</strong> – positional arguments passed to the transform callable.</li>
 <li><strong>**kwargs</strong> – keyword arguments passed to the transform callable.</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">A <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> containing the
 <a class="reference internal" href="#apache_beam.transforms.core.Filter" title="apache_beam.transforms.core.Filter"><code class="xref py py-func docutils literal"><span class="pre">Filter()</span></code></a> outputs.</p>
 </td>
 </tr>
 <tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection">PCollection</a></p>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><p class="first last"><a class="reference external" href="https://docs.python.org/2/library/exceptions.html#exceptions.TypeError" title="(in Python v2.7)"><code class="xref py py-exc docutils literal"><span class="pre">TypeError</span></code></a> – If the <strong>fn</strong> passed as argument is not a callable.
 Typical error is to pass a <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">DoFn</span></code></a> instance which is supported only
 for <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">ParDo</span></code></a>.</p>
 </td>
 </tr>
 </tbody>
 </table>
 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.CombineGlobally">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">CombineGlobally</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.transforms.ptransform.html#apache_beam.transforms.ptransform.PTransform" title="apache_beam.transforms.ptransform.PTransform"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransform</span></code></a></p>
 <p>A <a class="reference internal" href="#apache_beam.transforms.core.CombineGlobally" title="apache_beam.transforms.core.CombineGlobally"><code class="xref py py-class docutils literal"><span class="pre">CombineGlobally</span></code></a> transform.</p>
 <p>Reduces a <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> to a single value by
 progressively applying a <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> to portions of the
 <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> (and to intermediate values created
 thereby). See documentation in <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> for details on the specifics
 on how <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> s are applied.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>pcoll</strong> (<a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><em>PCollection</em></a>) – a <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> to be reduced into a single
 value.</li>
 <li><strong>fn</strong> (<a class="reference external" href="https://docs.python.org/2/library/functions.html#callable" title="(in Python v2.7)"><em>callable</em></a>) – a <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> object that will be called to
 progressively reduce the <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> into
 single values, or a callable suitable for wrapping by
 <code class="xref py py-class docutils literal"><span class="pre">CallableWrapperCombineFn</span></code>.</li>
 <li><strong>*args</strong> – positional arguments passed to the <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> object.</li>
 <li><strong>**kwargs</strong> – keyword arguments passed to the <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> object.</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Raises:</th><td class="field-body"><p class="first"><a class="reference external" href="https://docs.python.org/2/library/exceptions.html#exceptions.TypeError" title="(in Python v2.7)"><code class="xref py py-exc docutils literal"><span class="pre">TypeError</span></code></a> – If the output type of the input
 <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> is not compatible
 with <code class="docutils literal"><span class="pre">Iterable[A]</span></code>.</p>
 </td>
 </tr>
 <tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">A single-element
 <a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection"><code class="xref py py-class docutils literal"><span class="pre">PCollection</span></code></a> containing the main output of
 the <a class="reference internal" href="#apache_beam.transforms.core.CombineGlobally" title="apache_beam.transforms.core.CombineGlobally"><code class="xref py py-class docutils literal"><span class="pre">CombineGlobally</span></code></a> transform.</p>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last"><a class="reference internal" href="apache_beam.pvalue.html#apache_beam.pvalue.PCollection" title="apache_beam.pvalue.PCollection">PCollection</a></p>
 </td>
 </tr>
 </tbody>
 </table>
 <p>Note that the positional and keyword arguments will be processed in order
 to detect <code class="xref py py-class docutils literal"><span class="pre">PValue</span></code> s that will be computed as side
 inputs to the transform.
 During pipeline execution whenever the <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> object gets executed
 (i.e. any of the <a class="reference internal" href="#apache_beam.transforms.core.CombineFn" title="apache_beam.transforms.core.CombineFn"><code class="xref py py-class docutils literal"><span class="pre">CombineFn</span></code></a> methods get called), the
 <code class="xref py py-class docutils literal"><span class="pre">PValue</span></code> arguments will be replaced by their
 actual value in the exact position where they appear in the argument lists.</p>
 <dl class="attribute">
 <dt id="apache_beam.transforms.core.CombineGlobally.has_defaults">
 <code class="descname">has_defaults</code><em class="property"> = True</em><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.has_defaults" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="attribute">
 <dt id="apache_beam.transforms.core.CombineGlobally.as_view">
 <code class="descname">as_view</code><em class="property"> = False</em><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.as_view" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineGlobally.display_data">
 <code class="descname">display_data</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally.display_data"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.display_data" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineGlobally.default_label">
 <code class="descname">default_label</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally.default_label"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.default_label" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineGlobally.with_defaults">
 <code class="descname">with_defaults</code><span class="sig-paren">(</span><em>has_defaults=True</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally.with_defaults"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.with_defaults" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineGlobally.without_defaults">
 <code class="descname">without_defaults</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally.without_defaults"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.without_defaults" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineGlobally.as_singleton_view">
 <code class="descname">as_singleton_view</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally.as_singleton_view"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.as_singleton_view" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineGlobally.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineGlobally.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineGlobally.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.CombinePerKey">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">CombinePerKey</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransformWithSideInputs</span></code></p>
 <p>A per-key Combine transform.</p>
 <p>Identifies sets of values associated with the same key in the input
 PCollection, then applies a CombineFn to condense those sets to single
 values. See documentation in CombineFn for details on the specifics on how
 CombineFns are applied.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
 <li><strong>pcoll</strong> – input pcollection.</li>
 <li><strong>fn</strong> – instance of CombineFn to apply to all values under the same key in
 pcoll, or a callable whose signature is <code class="docutils literal"><span class="pre">f(iterable,</span> <span class="pre">*args,</span> <span class="pre">**kwargs)</span></code>
 (e.g., sum, max).</li>
 <li><strong>*args</strong> – arguments and side inputs, passed directly to the CombineFn.</li>
 <li><strong>**kwargs</strong> – arguments and side inputs, passed directly to the CombineFn.</li>
 </ul>
 </td>
 </tr>
 <tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first last">A PObject holding the result of the combine operation.</p>
 </td>
 </tr>
 </tbody>
 </table>
 <dl class="method">
 <dt id="apache_beam.transforms.core.CombinePerKey.display_data">
 <code class="descname">display_data</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.display_data"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.display_data" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombinePerKey.make_fn">
 <code class="descname">make_fn</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.make_fn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.make_fn" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombinePerKey.default_label">
 <code class="descname">default_label</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.default_label"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.default_label" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombinePerKey.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombinePerKey.default_type_hints">
 <code class="descname">default_type_hints</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.default_type_hints"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.default_type_hints" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombinePerKey.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.CombinePerKey.from_runner_api_parameter">
 <em class="property">static </em><code class="descname">from_runner_api_parameter</code><span class="sig-paren">(</span><em>combine_payload</em>, <em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombinePerKey.from_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombinePerKey.from_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.CombineValues">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">CombineValues</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineValues"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineValues" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransformWithSideInputs</span></code></p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineValues.make_fn">
 <code class="descname">make_fn</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineValues.make_fn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineValues.make_fn" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineValues.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineValues.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineValues.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.CombineValues.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineValues.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineValues.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.CombineValues.from_runner_api_parameter">
 <em class="property">static </em><code class="descname">from_runner_api_parameter</code><span class="sig-paren">(</span><em>combine_payload</em>, <em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#CombineValues.from_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.CombineValues.from_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.GroupByKey">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">GroupByKey</code><span class="sig-paren">(</span><em>label=None</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.transforms.ptransform.html#apache_beam.transforms.ptransform.PTransform" title="apache_beam.transforms.ptransform.PTransform"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransform</span></code></a></p>
 <p>A group by key transform.</p>
 <p>Processes an input PCollection consisting of key/value pairs represented as a
 tuple pair. The result is a PCollection where values having a common key are
 grouped together.  For example (a, 1), (b, 2), (a, 3) will result into
 (a, [1, 3]), (b, [2]).</p>
 <p>The implementation here is used only when run on the local direct runner.</p>
 <dl class="class">
 <dt id="apache_beam.transforms.core.GroupByKey.ReifyWindows">
 <em class="property">class </em><code class="descname">ReifyWindows</code><span class="sig-paren">(</span><em>*unused_args</em>, <em>**unused_kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey.ReifyWindows"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey.ReifyWindows" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.core.DoFn</span></code></a></p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.GroupByKey.ReifyWindows.process">
 <code class="descname">process</code><span class="sig-paren">(</span><em>element</em>, <em>window='WindowParam'</em>, <em>timestamp='TimestampParam'</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey.ReifyWindows.process"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey.ReifyWindows.process" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.GroupByKey.ReifyWindows.infer_output_type">
 <code class="descname">infer_output_type</code><span class="sig-paren">(</span><em>input_type</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey.ReifyWindows.infer_output_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey.ReifyWindows.infer_output_type" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.GroupByKey.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.GroupByKey.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>unused_context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.GroupByKey.from_runner_api_parameter">
 <em class="property">static </em><code class="descname">from_runner_api_parameter</code><span class="sig-paren">(</span><em>unused_payload</em>, <em>unused_context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#GroupByKey.from_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.GroupByKey.from_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.Partition">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">Partition</code><span class="sig-paren">(</span><em>fn</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Partition"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Partition" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransformWithSideInputs</span></code></p>
 <p>Split a PCollection into several partitions.</p>
 <p>Uses the specified PartitionFn to separate an input PCollection into the
 specified number of sub-PCollections.</p>
 <p>When apply()d, a Partition() PTransform requires the following:</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
 <li><strong>partitionfn</strong> – a PartitionFn, or a callable with the signature described in
 CallableWrapperPartitionFn.</li>
 <li><strong>n</strong> – number of output partitions.</li>
 </ul>
 </td>
 </tr>
 </tbody>
 </table>
 <p>The result of this PTransform is a simple list of the output PCollections
 representing each of n partitions, in order.</p>
 <dl class="class">
 <dt id="apache_beam.transforms.core.Partition.ApplyPartitionFnFn">
 <em class="property">class </em><code class="descname">ApplyPartitionFnFn</code><span class="sig-paren">(</span><em>*unused_args</em>, <em>**unused_kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Partition.ApplyPartitionFnFn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Partition.ApplyPartitionFnFn" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.core.DoFn</span></code></a></p>
 <p>A DoFn that applies a PartitionFn.</p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.Partition.ApplyPartitionFnFn.process">
 <code class="descname">process</code><span class="sig-paren">(</span><em>element</em>, <em>partitionfn</em>, <em>n</em>, <em>*args</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Partition.ApplyPartitionFnFn.process"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Partition.ApplyPartitionFnFn.process" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Partition.make_fn">
 <code class="descname">make_fn</code><span class="sig-paren">(</span><em>fn</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Partition.make_fn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Partition.make_fn" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Partition.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Partition.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Partition.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.Windowing">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">Windowing</code><span class="sig-paren">(</span><em>windowfn</em>, <em>triggerfn=None</em>, <em>accumulation_mode=None</em>, <em>timestamp_combiner=None</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Windowing"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Windowing" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference external" href="https://docs.python.org/2/library/functions.html#object" title="(in Python v2.7)"><code class="xref py py-class docutils literal"><span class="pre">object</span></code></a></p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.Windowing.is_default">
 <code class="descname">is_default</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Windowing.is_default"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Windowing.is_default" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Windowing.to_runner_api">
 <code class="descname">to_runner_api</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Windowing.to_runner_api"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Windowing.to_runner_api" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.Windowing.from_runner_api">
 <em class="property">static </em><code class="descname">from_runner_api</code><span class="sig-paren">(</span><em>proto</em>, <em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Windowing.from_runner_api"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Windowing.from_runner_api" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.WindowInto">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">WindowInto</code><span class="sig-paren">(</span><em>windowfn</em>, <em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="#apache_beam.transforms.core.ParDo" title="apache_beam.transforms.core.ParDo"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.core.ParDo</span></code></a></p>
 <p>A window transform assigning windows to each element of a PCollection.</p>
 <p>Transforms an input PCollection by applying a windowing function to each
 element.  Each transformed element in the result will be a WindowedValue
 element with the same input value and timestamp, with its new set of windows
 determined by the windowing function.</p>
 <p>Initializes a WindowInto transform.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>windowfn</strong> – Function to be used for windowing</td>
 </tr>
 </tbody>
 </table>
 <dl class="class">
 <dt id="apache_beam.transforms.core.WindowInto.WindowIntoFn">
 <em class="property">class </em><code class="descname">WindowIntoFn</code><span class="sig-paren">(</span><em>windowing</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.WindowIntoFn"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.WindowIntoFn" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="#apache_beam.transforms.core.DoFn" title="apache_beam.transforms.core.DoFn"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.core.DoFn</span></code></a></p>
 <p>A DoFn that applies a WindowInto operation.</p>
 <dl class="method">
 <dt id="apache_beam.transforms.core.WindowInto.WindowIntoFn.process">
 <code class="descname">process</code><span class="sig-paren">(</span><em>element</em>, <em>timestamp='TimestampParam'</em>, <em>window='WindowParam'</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.WindowIntoFn.process"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.WindowIntoFn.process" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.WindowInto.get_windowing">
 <code class="descname">get_windowing</code><span class="sig-paren">(</span><em>unused_inputs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.get_windowing"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.get_windowing" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.WindowInto.infer_output_type">
 <code class="descname">infer_output_type</code><span class="sig-paren">(</span><em>input_type</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.infer_output_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.infer_output_type" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.WindowInto.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcoll</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.WindowInto.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.WindowInto.from_runner_api_parameter">
 <em class="property">static </em><code class="descname">from_runner_api_parameter</code><span class="sig-paren">(</span><em>proto</em>, <em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#WindowInto.from_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.WindowInto.from_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.Flatten">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">Flatten</code><span class="sig-paren">(</span><em>**kwargs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Flatten"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Flatten" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.transforms.ptransform.html#apache_beam.transforms.ptransform.PTransform" title="apache_beam.transforms.ptransform.PTransform"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransform</span></code></a></p>
 <p>Merges several PCollections into a single PCollection.</p>
 <p>Copies all elements in 0 or more PCollections into a single output
 PCollection. If there are no input PCollections, the resulting PCollection
 will be empty (but see also kwargs below).</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>**kwargs</strong> – Accepts a single named argument “pipeline”, which specifies the
 pipeline that “owns” this PTransform. Ordinarily Flatten can obtain this
 information from one of the input PCollections, but if there are none (or
 if there’s a chance there may be none), this argument is the only way to
 provide pipeline information and should be considered mandatory.</td>
 </tr>
 </tbody>
 </table>
 <dl class="method">
 <dt id="apache_beam.transforms.core.Flatten.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pcolls</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Flatten.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Flatten.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Flatten.get_windowing">
 <code class="descname">get_windowing</code><span class="sig-paren">(</span><em>inputs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Flatten.get_windowing"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Flatten.get_windowing" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Flatten.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Flatten.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Flatten.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="staticmethod">
 <dt id="apache_beam.transforms.core.Flatten.from_runner_api_parameter">
 <em class="property">static </em><code class="descname">from_runner_api_parameter</code><span class="sig-paren">(</span><em>unused_parameter</em>, <em>unused_context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Flatten.from_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Flatten.from_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

 <dl class="class">
 <dt id="apache_beam.transforms.core.Create">
 <em class="property">class </em><code class="descclassname">apache_beam.transforms.core.</code><code class="descname">Create</code><span class="sig-paren">(</span><em>value</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Create"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Create" title="Permalink to this definition">¶</a></dt>
 <dd><p>Bases: <a class="reference internal" href="apache_beam.transforms.ptransform.html#apache_beam.transforms.ptransform.PTransform" title="apache_beam.transforms.ptransform.PTransform"><code class="xref py py-class docutils literal"><span class="pre">apache_beam.transforms.ptransform.PTransform</span></code></a></p>
 <p>A transform that creates a PCollection from an iterable.</p>
 <p>Initializes a Create transform.</p>
 <table class="docutils field-list" frame="void" rules="none">
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
 <tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>value</strong> – An object of values for the PCollection</td>
 </tr>
 </tbody>
 </table>
 <dl class="method">
 <dt id="apache_beam.transforms.core.Create.to_runner_api_parameter">
 <code class="descname">to_runner_api_parameter</code><span class="sig-paren">(</span><em>context</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Create.to_runner_api_parameter"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Create.to_runner_api_parameter" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Create.infer_output_type">
 <code class="descname">infer_output_type</code><span class="sig-paren">(</span><em>unused_input_type</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Create.infer_output_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Create.infer_output_type" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Create.get_output_type">
 <code class="descname">get_output_type</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Create.get_output_type"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Create.get_output_type" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Create.expand">
 <code class="descname">expand</code><span class="sig-paren">(</span><em>pbegin</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Create.expand"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Create.expand" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 <dl class="method">
 <dt id="apache_beam.transforms.core.Create.get_windowing">
 <code class="descname">get_windowing</code><span class="sig-paren">(</span><em>unused_inputs</em><span class="sig-paren">)</span><a class="reference internal" href="_modules/apache_beam/transforms/core.html#Create.get_windowing"><span class="viewcode-link">[source]</span></a><a class="headerlink" href="#apache_beam.transforms.core.Create.get_windowing" title="Permalink to this definition">¶</a></dt>
 <dd></dd></dl>

 </dd></dl>

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