parameters: (self, markName, direction=None)
return_statement: return self.tk.call(
              (self._w, 'mark', 'gravity', markName, direction))
docstring: Change the gravity of a mark MARKNAME to DIRECTION (LEFT or RIGHT).
          Return the current value if None is given for DIRECTION.
docstring_summary: Change the gravity of a mark MARKNAME to DIRECTION (LEFT or RIGHT).
          Return the current value if None is given for DIRECTION.
docstring_tokens: Change the gravity of a mark MARKNAME to DIRECTION ( LEFT or RIGHT ) . Return the current value if None is given for DIRECTION .
function: def mark_gravity(self, markName, direction=None):
          """Change the gravity of a mark MARKNAME to DIRECTION (LEFT or RIGHT).
          Return the current value if None is given for DIRECTION."""
          return self.tk.call(
              (self._w, 'mark', 'gravity', markName, direction))
function_tokens: def mark_gravity ( self , markName , direction = None ) : return self . tk . call ( ( self . _w , 'mark' , 'gravity' , markName , direction ) )