code: def guess_type(self, path):
          
  
          base, ext = posixpath.splitext(path)
          if ext in self.extensions_map:
              return self.extensions_map[ext]
          ext = ext.lower()
          if ext in self.extensions_map:
              return self.extensions_map[ext]
          else:
              return self.extensions_map['']
docs: Guess the type of a file.
  
          Argument is a PATH (a filename).
  
          Return value is a string of the form type/subtype,
          usable for a MIME Content-type header.
  
          The default implementation looks the file's extension
          up in the table self.extensions_map, using application/octet-stream
          as a default; however it would be permissible (if
          slow) to look inside the data to make a better guess.