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   <h1>Source code for apache_beam.io.gcp.bigquery_schema_tools</h1><div class="highlight"><pre>
 <span></span><span class="c1">#</span>
 <span class="c1"># Licensed to the Apache Software Foundation (ASF) under one or more</span>
 <span class="c1"># contributor license agreements.  See the NOTICE file distributed with</span>
 <span class="c1"># this work for additional information regarding copyright ownership.</span>
 <span class="c1"># The ASF licenses this file to You under the Apache License, Version 2.0</span>
 <span class="c1"># (the &quot;License&quot;); you may not use this file except in compliance with</span>
 <span class="c1"># the License.  You may obtain a copy of the License at</span>
 <span class="c1">#</span>
 <span class="c1">#    http://www.apache.org/licenses/LICENSE-2.0</span>
 <span class="c1">#</span>
 <span class="c1"># Unless required by applicable law or agreed to in writing, software</span>
 <span class="c1"># distributed under the License is distributed on an &quot;AS IS&quot; BASIS,</span>
 <span class="c1"># WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.</span>
 <span class="c1"># See the License for the specific language governing permissions and</span>
 <span class="c1"># limitations under the License.</span>
 <span class="c1">#</span>

 <span class="sd">&quot;&quot;&quot;Tools used tool work with Schema types in the context of BigQuery.</span>
 <span class="sd">Classes, constants and functions in this file are experimental and have no</span>
 <span class="sd">backwards compatibility guarantees.</span>
 <span class="sd">NOTHING IN THIS FILE HAS BACKWARDS COMPATIBILITY GUARANTEES.</span>
 <span class="sd">&quot;&quot;&quot;</span>

 <span class="kn">import</span> <span class="nn">datetime</span>
 <span class="kn">from</span> <span class="nn">typing</span> <span class="kn">import</span> <span class="n">Optional</span>
 <span class="kn">from</span> <span class="nn">typing</span> <span class="kn">import</span> <span class="n">Sequence</span>

 <span class="kn">import</span> <span class="nn">numpy</span> <span class="k">as</span> <span class="nn">np</span>

 <span class="kn">import</span> <span class="nn">apache_beam</span> <span class="k">as</span> <span class="nn">beam</span>
 <span class="kn">import</span> <span class="nn">apache_beam.io.gcp.bigquery_tools</span>
 <span class="kn">import</span> <span class="nn">apache_beam.typehints.schemas</span>
 <span class="kn">import</span> <span class="nn">apache_beam.utils.proto_utils</span>
 <span class="kn">import</span> <span class="nn">apache_beam.utils.timestamp</span>
 <span class="kn">from</span> <span class="nn">apache_beam.io.gcp.internal.clients</span> <span class="kn">import</span> <span class="n">bigquery</span>
 <span class="kn">from</span> <span class="nn">apache_beam.portability.api</span> <span class="kn">import</span> <span class="n">schema_pb2</span>
 <span class="kn">from</span> <span class="nn">apache_beam.transforms</span> <span class="kn">import</span> <span class="n">DoFn</span>

 <span class="c1"># BigQuery types as listed in</span>
 <span class="c1"># https://cloud.google.com/bigquery/docs/reference/standard-sql/data-types</span>
 <span class="c1"># with aliases (RECORD, BOOLEAN, FLOAT, INTEGER) as defined in</span>
 <span class="c1"># https://developers.google.com/resources/api-libraries/documentation/bigquery/v2/java/latest/com/google/api/services/bigquery/model/TableFieldSchema.html#setType-java.lang.String-</span>
 <span class="n">BIG_QUERY_TO_PYTHON_TYPES</span> <span class="o">=</span> <span class="p">{</span>
     <span class="s2">&quot;STRING&quot;</span><span class="p">:</span> <span class="nb">str</span><span class="p">,</span>
     <span class="s2">&quot;INTEGER&quot;</span><span class="p">:</span> <span class="n">np</span><span class="o">.</span><span class="n">int64</span><span class="p">,</span>
     <span class="s2">&quot;FLOAT64&quot;</span><span class="p">:</span> <span class="n">np</span><span class="o">.</span><span class="n">float64</span><span class="p">,</span>
     <span class="s2">&quot;FLOAT&quot;</span><span class="p">:</span> <span class="n">np</span><span class="o">.</span><span class="n">float64</span><span class="p">,</span>
     <span class="s2">&quot;BOOLEAN&quot;</span><span class="p">:</span> <span class="nb">bool</span><span class="p">,</span>
     <span class="s2">&quot;BYTES&quot;</span><span class="p">:</span> <span class="nb">bytes</span><span class="p">,</span>
     <span class="s2">&quot;TIMESTAMP&quot;</span><span class="p">:</span> <span class="n">apache_beam</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">timestamp</span><span class="o">.</span><span class="n">Timestamp</span>
     <span class="c1">#TODO(https://github.com/apache/beam/issues/20810):</span>
     <span class="c1"># Finish mappings for all BQ types</span>
 <span class="p">}</span>


 <div class="viewcode-block" id="generate_user_type_from_bq_schema"><a class="viewcode-back" href="../../../../apache_beam.io.gcp.bigquery_schema_tools.html#apache_beam.io.gcp.bigquery_schema_tools.generate_user_type_from_bq_schema">[docs]</a><span class="k">def</span> <span class="nf">generate_user_type_from_bq_schema</span><span class="p">(</span><span class="n">the_table_schema</span><span class="p">,</span> <span class="n">selected_fields</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
   <span class="c1">#type: (bigquery.TableSchema) -&gt; type</span>

 <span class="w">  </span><span class="sd">&quot;&quot;&quot;Convert a schema of type TableSchema into a pcollection element.</span>
 <span class="sd">      Args:</span>
 <span class="sd">        the_table_schema: A BQ schema of type TableSchema</span>
 <span class="sd">        selected_fields: if not None, the subset of fields to consider</span>
 <span class="sd">      Returns:</span>
 <span class="sd">        type: type that can be used to work with pCollections.</span>
 <span class="sd">  &quot;&quot;&quot;</span>

   <span class="n">the_schema</span> <span class="o">=</span> <span class="n">beam</span><span class="o">.</span><span class="n">io</span><span class="o">.</span><span class="n">gcp</span><span class="o">.</span><span class="n">bigquery_tools</span><span class="o">.</span><span class="n">get_dict_table_schema</span><span class="p">(</span>
       <span class="n">the_table_schema</span><span class="p">)</span>
   <span class="k">if</span> <span class="n">the_schema</span> <span class="o">==</span> <span class="p">{}:</span>
     <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s2">&quot;Encountered an empty schema&quot;</span><span class="p">)</span>
   <span class="n">field_names_and_types</span> <span class="o">=</span> <span class="p">[]</span>
   <span class="k">for</span> <span class="n">field</span> <span class="ow">in</span> <span class="n">the_schema</span><span class="p">[</span><span class="s1">&#39;fields&#39;</span><span class="p">]:</span>
     <span class="k">if</span> <span class="n">selected_fields</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span> <span class="ow">and</span> <span class="n">field</span><span class="p">[</span><span class="s1">&#39;name&#39;</span><span class="p">]</span> <span class="ow">not</span> <span class="ow">in</span> <span class="n">selected_fields</span><span class="p">:</span>
       <span class="k">continue</span>
     <span class="k">if</span> <span class="n">field</span><span class="p">[</span><span class="s1">&#39;type&#39;</span><span class="p">]</span> <span class="ow">in</span> <span class="n">BIG_QUERY_TO_PYTHON_TYPES</span><span class="p">:</span>
       <span class="n">typ</span> <span class="o">=</span> <span class="n">bq_field_to_type</span><span class="p">(</span><span class="n">field</span><span class="p">[</span><span class="s1">&#39;type&#39;</span><span class="p">],</span> <span class="n">field</span><span class="p">[</span><span class="s1">&#39;mode&#39;</span><span class="p">])</span>
     <span class="k">else</span><span class="p">:</span>
       <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span>
           <span class="sa">f</span><span class="s2">&quot;Encountered &quot;</span>
           <span class="sa">f</span><span class="s2">&quot;an unsupported type: </span><span class="si">{</span><span class="n">field</span><span class="p">[</span><span class="s1">&#39;type&#39;</span><span class="p">]</span><span class="si">!r}</span><span class="s2">&quot;</span><span class="p">)</span>
     <span class="n">field_names_and_types</span><span class="o">.</span><span class="n">append</span><span class="p">((</span><span class="n">field</span><span class="p">[</span><span class="s1">&#39;name&#39;</span><span class="p">],</span> <span class="n">typ</span><span class="p">))</span>
   <span class="n">sample_schema</span> <span class="o">=</span> <span class="n">beam</span><span class="o">.</span><span class="n">typehints</span><span class="o">.</span><span class="n">schemas</span><span class="o">.</span><span class="n">named_fields_to_schema</span><span class="p">(</span>
       <span class="n">field_names_and_types</span><span class="p">)</span>
   <span class="n">usertype</span> <span class="o">=</span> <span class="n">beam</span><span class="o">.</span><span class="n">typehints</span><span class="o">.</span><span class="n">schemas</span><span class="o">.</span><span class="n">named_tuple_from_schema</span><span class="p">(</span><span class="n">sample_schema</span><span class="p">)</span>
   <span class="k">return</span> <span class="n">usertype</span></div>


 <div class="viewcode-block" id="bq_field_to_type"><a class="viewcode-back" href="../../../../apache_beam.io.gcp.bigquery_schema_tools.html#apache_beam.io.gcp.bigquery_schema_tools.bq_field_to_type">[docs]</a><span class="k">def</span> <span class="nf">bq_field_to_type</span><span class="p">(</span><span class="n">field</span><span class="p">,</span> <span class="n">mode</span><span class="p">):</span>
   <span class="k">if</span> <span class="n">mode</span> <span class="o">==</span> <span class="s1">&#39;NULLABLE&#39;</span> <span class="ow">or</span> <span class="n">mode</span> <span class="ow">is</span> <span class="kc">None</span> <span class="ow">or</span> <span class="n">mode</span> <span class="o">==</span> <span class="s1">&#39;&#39;</span><span class="p">:</span>
     <span class="k">return</span> <span class="n">Optional</span><span class="p">[</span><span class="n">BIG_QUERY_TO_PYTHON_TYPES</span><span class="p">[</span><span class="n">field</span><span class="p">]]</span>
   <span class="k">elif</span> <span class="n">mode</span> <span class="o">==</span> <span class="s1">&#39;REPEATED&#39;</span><span class="p">:</span>
     <span class="k">return</span> <span class="n">Sequence</span><span class="p">[</span><span class="n">BIG_QUERY_TO_PYTHON_TYPES</span><span class="p">[</span><span class="n">field</span><span class="p">]]</span>
   <span class="k">elif</span> <span class="n">mode</span> <span class="o">==</span> <span class="s1">&#39;REQUIRED&#39;</span><span class="p">:</span>
     <span class="k">return</span> <span class="n">BIG_QUERY_TO_PYTHON_TYPES</span><span class="p">[</span><span class="n">field</span><span class="p">]</span>
   <span class="k">else</span><span class="p">:</span>
     <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;Encountered an unsupported mode: </span><span class="si">{</span><span class="n">mode</span><span class="si">!r}</span><span class="s2">&quot;</span><span class="p">)</span></div>


 <div class="viewcode-block" id="convert_to_usertype"><a class="viewcode-back" href="../../../../apache_beam.io.gcp.bigquery_schema_tools.html#apache_beam.io.gcp.bigquery_schema_tools.convert_to_usertype">[docs]</a><span class="k">def</span> <span class="nf">convert_to_usertype</span><span class="p">(</span><span class="n">table_schema</span><span class="p">,</span> <span class="n">selected_fields</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
   <span class="n">usertype</span> <span class="o">=</span> <span class="n">generate_user_type_from_bq_schema</span><span class="p">(</span><span class="n">table_schema</span><span class="p">,</span> <span class="n">selected_fields</span><span class="p">)</span>
   <span class="k">return</span> <span class="n">beam</span><span class="o">.</span><span class="n">ParDo</span><span class="p">(</span><span class="n">BeamSchemaConversionDoFn</span><span class="p">(</span><span class="n">usertype</span><span class="p">))</span></div>


 <div class="viewcode-block" id="BeamSchemaConversionDoFn"><a class="viewcode-back" href="../../../../apache_beam.io.gcp.bigquery_schema_tools.html#apache_beam.io.gcp.bigquery_schema_tools.BeamSchemaConversionDoFn">[docs]</a><span class="k">class</span> <span class="nc">BeamSchemaConversionDoFn</span><span class="p">(</span><span class="n">DoFn</span><span class="p">):</span>
   <span class="k">def</span> <span class="fm">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">pcoll_val_ctor</span><span class="p">):</span>
     <span class="bp">self</span><span class="o">.</span><span class="n">_pcoll_val_ctor</span> <span class="o">=</span> <span class="n">pcoll_val_ctor</span>

 <div class="viewcode-block" id="BeamSchemaConversionDoFn.process"><a class="viewcode-back" href="../../../../apache_beam.io.gcp.bigquery_schema_tools.html#apache_beam.io.gcp.bigquery_schema_tools.BeamSchemaConversionDoFn.process">[docs]</a>  <span class="k">def</span> <span class="nf">process</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dict_of_tuples</span><span class="p">):</span>
     <span class="k">for</span> <span class="n">k</span><span class="p">,</span> <span class="n">v</span> <span class="ow">in</span> <span class="n">dict_of_tuples</span><span class="o">.</span><span class="n">items</span><span class="p">():</span>
       <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">v</span><span class="p">,</span> <span class="n">datetime</span><span class="o">.</span><span class="n">datetime</span><span class="p">):</span>
         <span class="n">dict_of_tuples</span><span class="p">[</span><span class="n">k</span><span class="p">]</span> <span class="o">=</span> <span class="n">beam</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">timestamp</span><span class="o">.</span><span class="n">Timestamp</span><span class="o">.</span><span class="n">from_utc_datetime</span><span class="p">(</span><span class="n">v</span><span class="p">)</span>
     <span class="k">yield</span> <span class="bp">self</span><span class="o">.</span><span class="n">_pcoll_val_ctor</span><span class="p">(</span><span class="o">**</span><span class="n">dict_of_tuples</span><span class="p">)</span></div>

 <div class="viewcode-block" id="BeamSchemaConversionDoFn.infer_output_type"><a class="viewcode-back" href="../../../../apache_beam.io.gcp.bigquery_schema_tools.html#apache_beam.io.gcp.bigquery_schema_tools.BeamSchemaConversionDoFn.infer_output_type">[docs]</a>  <span class="k">def</span> <span class="nf">infer_output_type</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">input_type</span><span class="p">):</span>
     <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_pcoll_val_ctor</span></div>

   <span class="nd">@classmethod</span>
   <span class="k">def</span> <span class="nf">_from_serialized_schema</span><span class="p">(</span><span class="bp">cls</span><span class="p">,</span> <span class="n">schema_str</span><span class="p">):</span>
     <span class="k">return</span> <span class="bp">cls</span><span class="p">(</span>
         <span class="n">apache_beam</span><span class="o">.</span><span class="n">typehints</span><span class="o">.</span><span class="n">schemas</span><span class="o">.</span><span class="n">named_tuple_from_schema</span><span class="p">(</span>
             <span class="n">apache_beam</span><span class="o">.</span><span class="n">utils</span><span class="o">.</span><span class="n">proto_utils</span><span class="o">.</span><span class="n">parse_Bytes</span><span class="p">(</span>
                 <span class="n">schema_str</span><span class="p">,</span> <span class="n">schema_pb2</span><span class="o">.</span><span class="n">Schema</span><span class="p">)))</span>

   <span class="k">def</span> <span class="nf">__reduce__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
     <span class="c1"># when pickling, use bytes representation of the schema.</span>
     <span class="k">return</span> <span class="p">(</span>
         <span class="bp">self</span><span class="o">.</span><span class="n">_from_serialized_schema</span><span class="p">,</span>
         <span class="p">(</span>
             <span class="n">beam</span><span class="o">.</span><span class="n">typehints</span><span class="o">.</span><span class="n">schemas</span><span class="o">.</span><span class="n">named_tuple_to_schema</span><span class="p">(</span>
                 <span class="bp">self</span><span class="o">.</span><span class="n">_pcoll_val_ctor</span><span class="p">)</span><span class="o">.</span><span class="n">SerializeToString</span><span class="p">(),</span> <span class="p">))</span></div>
 </pre></div>

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