(self)
return not af or all(i == af[i] for i in xrange(self.size))
Returns True if the Permutation is an identity permutation.

        Examples
        ========

        >>> from sympy.combinatorics.permutations import Permutation
        >>> p = Permutation([])
        >>> p.is_Identity
        True
        >>> p = Permutation([[0], [1], [2]])
        >>> p.is_Identity
        True
        >>> p = Permutation([0, 1, 2])
        >>> p.is_Identity
        True
        >>> p = Permutation([0, 2, 1])
        >>> p.is_Identity
        False

        See Also
        ========

        order
Returns True if the Permutation is an identity permutation.
Returns True if the Permutation is an identity permutation .
def is_Identity(self):
        """
        Returns True if the Permutation is an identity permutation.

        Examples
        ========

        >>> from sympy.combinatorics.permutations import Permutation
        >>> p = Permutation([])
        >>> p.is_Identity
        True
        >>> p = Permutation([[0], [1], [2]])
        >>> p.is_Identity
        True
        >>> p = Permutation([0, 1, 2])
        >>> p.is_Identity
        True
        >>> p = Permutation([0, 2, 1])
        >>> p.is_Identity
        False

        See Also
        ========

        order
        """
        af = self.array_form
        return not af or all(i == af[i] for i in xrange(self.size))
def is_Identity ( self ) : af = self . array_form return not af or all ( i == af [ i ] for i in xrange ( self . size ) )