parameters: (self, pattern)
docstring: Adds a :class:`Pattern` to the :class:`PatternSet`
docstring_summary: Adds a :class:`Pattern` to the :class:`PatternSet`
docstring_tokens: Adds a : class : Pattern to the : class : PatternSet
function: def append(self, pattern):
          """Adds a :class:`Pattern` to the :class:`PatternSet`"""
          assert isinstance(pattern, Pattern)
          self.patterns.append(pattern)
          if self._all_files is not None:
              self._all_files = self._all_files or pattern.all_files()
function_tokens: def append ( self , pattern ) : assert isinstance ( pattern , Pattern ) self . patterns . append ( pattern ) if self . _all_files is not None : self . _all_files = self . _all_files or pattern . all_files ( )