---
title: "Keys"
---
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# Keys

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{{< button-pydoc path="apache_beam.transforms.util" class="Keys" >}}

Takes a collection of key-value pairs and returns the key of each element.

## Example

In the following example, we create a pipeline with a `PCollection` of key-value pairs.
Then, we apply `Keys` to extract the keys and discard the values.

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{{< code_sample "sdks/python/apache_beam/examples/snippets/transforms/elementwise/keys.py" keys >}}
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Output `PCollection` after `Keys`:
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{{< code_sample "sdks/python/apache_beam/examples/snippets/transforms/elementwise/keys_test.py" icons >}}
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  py="sdks/python/apache_beam/examples/snippets/transforms/elementwise/keys.py"
  notebook="examples/notebooks/documentation/transforms/python/elementwise/keys" >}}

## Related transforms

* [KvSwap](/documentation/transforms/python/elementwise/kvswap) swaps the key and value of each element.
* [Values](/documentation/transforms/python/elementwise/values) for extracting the value of each element.

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