Class DataSource

numpy/lib/_datasource.py:196–529

DataSource(destpath='.') A generic data source file (file, http, ftp, ...). DataSources can be local files or remote files/URLs. The files may also be compressed or uncompressed. DataSource hides some of the low-level details of downloading the file, allowing you to simply pa

@set_module('numpy.lib.npyio')
class DataSource:
    """
    DataSource(destpath='.')

    A generic data source file (file, http, ftp, ...).

    DataSources can be local files or remote files/URLs.  The files may
    also be compressed or uncompressed. DataSource hides some of the
    low-level details of downloading the file, allowing you to simply pass
    in a valid file path (or URL) and obtain a file object.

    Parameters
    ----------
    destpath : str or None, optional
        Path to the directory where the source file gets downloaded to for
        use.  If `destpath` is None, a temporary directory will be created.
        The default path is the current directory.

    Notes
    -----
    URLs require a scheme string (``http://``) to be used, without it they
    will fail::

        >>> repos = np.lib.npyio.DataSource()
        >>> repos.exists('www.google.com/index.html')
        False
        >>> repos.exists('http://www.google.com/index.html')
        True

    Temporary directories are deleted when the DataSource is deleted.

    Examples
    --------
    ::

        >>> ds = np.lib.npyio.DataSource('/home/guido')
        >>> urlname = 'http://www.google.com/'
        >>> gfile = ds.open('http://www.google.com/')
        >>> ds.abspath(urlname)
        '/home/guido/www.google.com/index.html'

        >>> ds = np.lib.npyio.DataSource(None)  # use with temporary file
        >>> ds.open('/home/guido/foobar.txt')
        <open file '/home/guido.foobar.txt', mode 'r' at 0x91d4430>
        >>> ds.abspath('/home/guido/foobar.txt')
        '/tmp/.../home/guido/foobar.txt'

    """

    def __init__(self, destpath=os.curdir):
        """Create a DataSource with a local path at destpath."""
        if destpath:
            self._destpath = os.path.abspath(destpath)
            self._istmpdest = False
        else:
            import tempfile  # deferring import to improve startup time
            self._destpath = tempfile.mkdtemp()
            self._istmpdest = True