code: def strip_format(self, str_and_format):
          
          m = re.match("(.+)\.([a-zA-Z]\w*)$", str_and_format)
          if (m):
              # There is a format string at end, chop off and store
              str_and_format = m.group(1)
              self.format = (m.group(2) if (m.group(2) is not None) else '')
          return(str_and_format)
docs: Look for optional .fmt at end of URI.
  
          The format must start with letter. Note that we want to catch
          the case of a dot and no format (format='') which is different
          from no dot (format=None)
  
          Sets self.format as side effect, returns possibly modified string