Merge pull request #12472 from davidcavazos/sum-docs
[BEAM-7390] Add sum code snippets
diff --git a/website/www/site/content/en/documentation/transforms/python/aggregation/sum.md b/website/www/site/content/en/documentation/transforms/python/aggregation/sum.md
index 8d49f5b..a9aef38 100644
--- a/website/www/site/content/en/documentation/transforms/python/aggregation/sum.md
+++ b/website/www/site/content/en/documentation/transforms/python/aggregation/sum.md
@@ -17,7 +17,61 @@
# Sum
-## Examples
-See [BEAM-7390](https://issues.apache.org/jira/browse/BEAM-7390) for updates.
+{{< localstorage language language-py >}}
-## Related transforms
\ No newline at end of file
+{{< button-pydoc path="apache_beam.transforms.core" class="CombineGlobally" >}}
+
+Sums all the elements within each aggregation.
+
+## Examples
+
+In the following example, we create a pipeline with a `PCollection`.
+Then, we get the sum of all the element values in different ways.
+
+### Example 1: Sum of the elements in a PCollection
+
+We use `Combine.Globally()` to get sum of all the element values from the *entire* `PCollection`.
+
+{{< highlight py >}}
+{{< code_sample "sdks/python/apache_beam/examples/snippets/transforms/aggregation/sum.py" sum_globally >}}
+{{< /highlight >}}
+
+{{< paragraph class="notebook-skip" >}}
+Output:
+{{< /paragraph >}}
+
+{{< highlight class="notebook-skip" >}}
+{{< code_sample "sdks/python/apache_beam/examples/snippets/transforms/aggregation/sum_test.py" total >}}
+{{< /highlight >}}
+
+{{< buttons-code-snippet
+ py="sdks/python/apache_beam/examples/snippets/transforms/aggregation/sum.py" >}}
+
+### Example 2: Sum of the elements for each key
+
+We use `Combine.PerKey()` to get the sum of all the element values for each unique key in a `PCollection` of key-values.
+
+{{< highlight py >}}
+{{< code_sample "sdks/python/apache_beam/examples/snippets/transforms/aggregation/sum.py" sum_per_key >}}
+{{< /highlight >}}
+
+{{< paragraph class="notebook-skip" >}}
+Output:
+{{< /paragraph >}}
+
+{{< highlight class="notebook-skip" >}}
+{{< code_sample "sdks/python/apache_beam/examples/snippets/transforms/aggregation/sum_test.py" totals_per_key >}}
+{{< /highlight >}}
+
+{{< buttons-code-snippet
+ py="sdks/python/apache_beam/examples/snippets/transforms/aggregation/sum.py" >}}
+
+## Related transforms
+
+* [CombineGlobally](/documentation/transforms/python/aggregation/combineglobally)
+* [CombinePerKey](/documentation/transforms/python/aggregation/combineperkey)
+* [Max](/documentation/transforms/python/aggregation/max)
+* [Mean](/documentation/transforms/python/aggregation/mean)
+* [Min](/documentation/transforms/python/aggregation/min)
+
+{{< button-pydoc path="apache_beam.transforms.core" class="CombineGlobally" >}}
diff --git a/website/www/site/content/en/documentation/transforms/python/overview.md b/website/www/site/content/en/documentation/transforms/python/overview.md
index d648ac7..059abcb 100644
--- a/website/www/site/content/en/documentation/transforms/python/overview.md
+++ b/website/www/site/content/en/documentation/transforms/python/overview.md
@@ -60,7 +60,7 @@
<tr><td><a href="/documentation/transforms/python/aggregation/mean">Mean</a></td><td>Computes the average within each aggregation.</td></tr>
<tr><td><a href="/documentation/transforms/python/aggregation/min">Min</a></td><td>Gets the element with the minimum value within each aggregation.</td></tr>
<tr><td><a href="/documentation/transforms/python/aggregation/sample">Sample</a></td><td>Randomly select some number of elements from each aggregation.</td></tr>
- <tr><td>Sum</td><td>Not available.</td></tr>
+ <tr><td><a href="/documentation/transforms/python/aggregation/sum">Sum</a></td><td>Sums all the elements within each aggregation.</td></tr>
<tr><td><a href="/documentation/transforms/python/aggregation/top">Top</a></td><td>Compute the largest element(s) in each aggregation.</td></tr>
</table>
diff --git a/website/www/site/layouts/partials/section-menu/en/documentation.html b/website/www/site/layouts/partials/section-menu/en/documentation.html
index fd35a21bd..f715f0c 100644
--- a/website/www/site/layouts/partials/section-menu/en/documentation.html
+++ b/website/www/site/layouts/partials/section-menu/en/documentation.html
@@ -205,6 +205,7 @@
<li><a href="/documentation/transforms/python/aggregation/mean/">Mean</a></li>
<li><a href="/documentation/transforms/python/aggregation/min/">Min</a></li>
<li><a href="/documentation/transforms/python/aggregation/sample/">Sample</a></li>
+ <li><a href="/documentation/transforms/python/aggregation/sum/">Sum</a></li>
<li><a href="/documentation/transforms/python/aggregation/top/">Top</a></li>
</ul>
</li>
