parameters: (self, n=None, delay=None)
docstring: Turns turtle animation on/off and set delay for update drawings.
  
          Optional arguments:
          n -- nonnegative  integer
          delay -- nonnegative  integer
  
          If n is given, only each n-th regular screen update is really performed.
          (Can be used to accelerate the drawing of complex graphics.)
          Second arguments sets delay value (see RawTurtle.delay())
  
          Example (for a TurtleScreen instance named screen):
          >>> screen.tracer(8, 25)
          >>> dist = 2
          >>> for i in range(200):
          ...     fd(dist)
          ...     rt(90)
          ...     dist += 2
docstring_summary: Turns turtle animation on/off and set delay for update drawings.
docstring_tokens: Turns turtle animation on / off and set delay for update drawings .
function: def tracer(self, n=None, delay=None):
          """Turns turtle animation on/off and set delay for update drawings.
  
          Optional arguments:
          n -- nonnegative  integer
          delay -- nonnegative  integer
  
          If n is given, only each n-th regular screen update is really performed.
          (Can be used to accelerate the drawing of complex graphics.)
          Second arguments sets delay value (see RawTurtle.delay())
  
          Example (for a TurtleScreen instance named screen):
          >>> screen.tracer(8, 25)
          >>> dist = 2
          >>> for i in range(200):
          ...     fd(dist)
          ...     rt(90)
          ...     dist += 2
          """
          if n is None:
              return self._tracing
          self._tracing = int(n)
          self._updatecounter = 0
          if delay is not None:
              self._delayvalue = int(delay)
          if self._tracing:
              self.update()
function_tokens: def tracer ( self , n = None , delay = None ) : if n is None : return self . _tracing self . _tracing = int ( n ) self . _updatecounter = 0 if delay is not None : self . _delayvalue = int ( delay ) if self . _tracing : self . update ( )