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