request.fetch

Request copies of relational datasets.

fetch(name, version=None)

Get a dataset with a name/version. Return path to a zipfile.

Something else.

Parameters:

Name	Type	Description	Default
name	str	Dataset name, usually lowercase with underscores.	required
version	Optional[str]	Dataset version. Downloads a default (v0.0.3) if not provided.	None

Returns:

Type	Description
str	A string representing the path to the downloaded dataset. For example:
str	```python
str	'/home/user/relational_datasets/toy_cancer_v0.0.3.zip'
str	```
str	The path is converted to a string from a pathlib object, so it should
str	work cross-platform.

Raises:

Type	Description
urllib.error.URLError	If the data is not in the cache and cannot be downloaded, a failed request will raise this exception.

Examples:

Fetch toy_cancer dataset, version v0.0.3:

from relational_datasets import fetch

fetch('toy_cancer', 'v0.0.3')
# '/home/user/relational_datasets/toy_cancer_v0.0.3.zip'

Source code in relational_datasets/request.py

def fetch(name: str, version: Optional[str] = None) -> str:
    """Get a dataset with a name/version. Return path to a zipfile.

    Something else.

    Arguments:
        name: Dataset name, usually lowercase with underscores.
        version: Dataset version. Downloads a default (`v0.0.3`) if not provided.

    Returns:
        A string representing the path to the downloaded dataset. For example:

        ```python
        '/home/user/relational_datasets/toy_cancer_v0.0.3.zip'
        ```

        The path is converted to a string from a `pathlib` object, so it should
        work cross-platform.

    Raises:
        urllib.error.URLError: If the data is not in the cache and cannot be
            downloaded, a failed request will raise this exception.

    Examples:

    Fetch `toy_cancer` dataset, version `v0.0.3`:

    ```python
    from relational_datasets import fetch

    fetch('toy_cancer', 'v0.0.3')
    # '/home/user/relational_datasets/toy_cancer_v0.0.3.zip'
    ```
    """

    # TODO(hayesall): This logic might be moved into the same function.
    data_file = _make_file_path(name, version)
    if data_file.is_file():
        return str(data_file)

    # Else the data needs to be downloaded.

    download_url = _make_data_url(name, version)

    with urlopen(download_url) as url:
        data = BytesIO(url.read())

    with open(data_file, "wb") as _fh:
        _fh.write(data.getbuffer())

    return str(data_file)

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Last update: June 20, 2022