(self, key)
return self._dict[sympify(key)]
x.__getitem__(y) <==> x[y]
x.__getitem__(y) <==> x[y]
x . __getitem__ ( y ) < == > x [ y ]
def __getitem__(self, key):
        """x.__getitem__(y) <==> x[y]"""
        return self._dict[sympify(key)]
def __getitem__ ( self , key ) : return self . _dict [ sympify ( key ) ]