Test if path exists.
Test if path exists as (and in this order):
| Parameters : | path : str 
  | 
|---|---|
| Returns : | out : bool 
  | 
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.