> For the complete documentation index, see [llms.txt](https://gitbook-docs.coinmetrics.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gitbook-docs.coinmetrics.io/python-api-client/reference/data-collection.md).

# DataCollection

```python
class coinmetrics._data_collection.DataCollection(
    data_retrieval_function,
    endpoint,
    url_params,
    csv_export_supported=True,
    client=None,
    paginated=True,
    **kwargs,
)
```

Bases: [`object`](https://docs.python.org/3/library/functions.html#object)

Lazy wrapper around a Coin Metrics REST endpoint response.

Every REST method on [`CoinMetricsClient`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/1MQgB4ZdN4XhwS0frkJK#coinmetrics.api_client.CoinMetricsClient) returns a `DataCollection`. It iterates over rows on demand (with transparent paging) and exposes helpers for converting the response into common Python data structures:

* [`to_dataframe()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/jGrDH5JaWpvotMblCMHs#coinmetrics._data_collection.DataCollection.to_dataframe) -- materialize into a pandas or polars dataframe.
* [`to_list()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/E36GlrFGzDQIWVNyjSde#coinmetrics._data_collection.DataCollection.to_list) -- materialize into `List[Dict[str, Any]]`.
* [`export_to_csv()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/dblxEhbbZEYyuQ4ISwTy#coinmetrics._data_collection.DataCollection.export_to_csv) -- stream the response into a CSV file or buffer.
* [`export_to_json()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/qzwE7iheljADRY7bRvns#coinmetrics._data_collection.DataCollection.export_to_json) -- stream the response into a JSON file or buffer.
* [`export_to_parquet()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/bBcnm9NWRw5g0vhPne7u#coinmetrics._data_collection.DataCollection.export_to_parquet) -- stream the response into a Parquet file.
* [`parallel()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/hviDNipdzNiWKvqvZTO3#coinmetrics._data_collection.DataCollection.parallel) -- return a [`ParallelDataCollection`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/eQIronmREyzwFm5VAeq6#coinmetrics._data_collection.ParallelDataCollection) that splits the request across worker threads. The result can be chained with [`to_dataframe()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/jGrDH5JaWpvotMblCMHs#coinmetrics._data_collection.DataCollection.to_dataframe), [`to_list()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/E36GlrFGzDQIWVNyjSde#coinmetrics._data_collection.DataCollection.to_list), [`export_to_csv_files()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/mpWKMwBhI1J9LP92Dibv#coinmetrics._data_collection.ParallelDataCollection.export_to_csv_files), [`export_to_json_files()`](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/YVD4T1nPHg9pO8VK9Hc8#coinmetrics._data_collection.ParallelDataCollection.export_to_json_files), and so on.
* **Parameters:**
  * **data\_retrieval\_function** (*DataRetrievalFuncType*)
  * **endpoint** ([*str*](https://docs.python.org/3/library/stdtypes.html#str))
  * **url\_params** (*Dict* *\[*[*str*](https://docs.python.org/3/library/stdtypes.html#str) *,* *UrlParamTypes* *]*)
  * **csv\_export\_supported** ([*bool*](https://docs.python.org/3/library/functions.html#bool))
  * **client** (*Optional* *\[*[*CoinMetricsClient*](https://gitbook-docs.coinmetrics.io/python-api-client/reference/pages/1MQgB4ZdN4XhwS0frkJK#coinmetrics.api_client.CoinMetricsClient) *]*)
  * **paginated** ([*bool*](https://docs.python.org/3/library/functions.html#bool))
  * **kwargs** (*Any*)

### Methods

* [`DataCollection.get_schema_field_names`](/python-api-client/reference/data-collection/get_schema_field_names.md)
* [`DataCollection.first_page`](/python-api-client/reference/data-collection/first_page.md)
* [`DataCollection.to_list`](/python-api-client/reference/data-collection/to_list.md)
* [`DataCollection.export_to_csv`](/python-api-client/reference/data-collection/export_to_csv.md)
* [`DataCollection.export_to_json`](/python-api-client/reference/data-collection/export_to_json.md)
* [`DataCollection.export_to_parquet`](/python-api-client/reference/data-collection/export_to_parquet.md)
* [`DataCollection.to_dataframe`](/python-api-client/reference/data-collection/to_dataframe.md)
* [`DataCollection.to_lazyframe`](/python-api-client/reference/data-collection/to_lazyframe.md)
* [`DataCollection.parallel`](/python-api-client/reference/data-collection/parallel.md)


---

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