code: def get_source(self, path_or_url):
          
          if path_or_url.startswith(('http://', 'https://')):
              try:
                  return urlopen(path_or_url)
              except IOError:
                  return None
  
          fullpath = path_or_url
          if not os.path.isabs(path_or_url):
              fullpath = os.path.join(self.base_path, path_or_url)
          try:
              return io.open(fullpath, 'rb')
          except IOError:
              return None
docs: Returns the source image file descriptor.
  
          path_or_url:
              Path to the source image as an absolute path, a path relative
              to `self.base_path` or a URL beginning with `http[s]`