Method exists

numpy/lib/_datasource.py:431–485

Test if path exists. Test if `path` exists as (and in this order): - a local file. - a remote URL that has been downloaded and stored locally in the `DataSource` directory. - a remote URL that has not been downloaded, but is valid and ac

(self, path)

        return path

    def exists(self, path):
        """
        Test if path exists.

        Test if `path` exists as (and in this order):

        - a local file.
        - a remote URL that has been downloaded and stored locally in the
          `DataSource` directory.
        - a remote URL that has not been downloaded, but is valid and
          accessible.

        Parameters
        ----------
        path : str
            Can be a local file or a remote URL.

        Returns
        -------
        out : bool
            True if `path` exists.

        Notes
        -----
        When `path` is an URL, `exists` will return True if it's either
        stored locally in the `DataSource` directory, or is a valid remote
        URL.  `DataSource` does not discriminate between the two, the file
        is accessible if it exists in either location.

        """

        # First test for local path
        if os.path.exists(path):
            return True

        # We import this here because importing urllib is slow and
        # a significant fraction of numpy's total import time.
        from urllib.request import urlopen
        from urllib.error import URLError

        # Test cached url
        upath = self.abspath(path)
        if os.path.exists(upath):
            return True

        # Test remote url
        if self._isurl(path):
            try:
                netfile = urlopen(path)
                netfile.close()
                del(netfile)
                return True
            except URLError:
                return False
        return False

    def open(self, path, mode='r', encoding=None, newline=None):
        """