parameters: (self, key, message)
docstring: Replace the keyed message; raise KeyError if it doesn't exist.
docstring_summary: Replace the keyed message; raise KeyError if it doesn't exist.
docstring_tokens: Replace the keyed message ; raise KeyError if it doesn t exist .
function: def __setitem__(self, key, message):
          """Replace the keyed message; raise KeyError if it doesn't exist."""
          old_subpath = self._lookup(key)
          temp_key = self.add(message)
          temp_subpath = self._lookup(temp_key)
          if isinstance(message, MaildirMessage):
              # temp's subdir and suffix were specified by message.
              dominant_subpath = temp_subpath
          else:
              # temp's subdir and suffix were defaults from add().
              dominant_subpath = old_subpath
          subdir = os.path.dirname(dominant_subpath)
          if self.colon in dominant_subpath:
              suffix = self.colon + dominant_subpath.split(self.colon)[-1]
          else:
              suffix = ''
          self.discard(key)
          tmp_path = os.path.join(self._path, temp_subpath)
          new_path = os.path.join(self._path, subdir, key + suffix)
          if isinstance(message, MaildirMessage):
              os.utime(tmp_path,
                       (os.path.getatime(tmp_path), message.get_date()))
          # No file modification should be done after the file is moved to its
          # final position in order to prevent race conditions with changes
          # from other programs
          os.rename(tmp_path, new_path)
function_tokens: def __setitem__ ( self , key , message ) : old_subpath = self . _lookup ( key ) temp_key = self . add ( message ) temp_subpath = self . _lookup ( temp_key ) if isinstance ( message , MaildirMessage ) : # temp's subdir and suffix were specified by message. dominant_subpath = temp_subpath else : # temp's subdir and suffix were defaults from add(). dominant_subpath = old_subpath subdir = os . path . dirname ( dominant_subpath ) if self . colon in dominant_subpath : suffix = self . colon + dominant_subpath . split ( self . colon ) [ - 1 ] else : suffix = '' self . discard ( key ) tmp_path = os . path . join ( self . _path , temp_subpath ) new_path = os . path . join ( self . _path , subdir , key + suffix ) if isinstance ( message , MaildirMessage ) : os . utime ( tmp_path , ( os . path . getatime ( tmp_path ) , message . get_date ( ) ) ) # No file modification should be done after the file is moved to its # final position in order to prevent race conditions with changes # from other programs os . rename ( tmp_path , new_path )