# Python | SymPy Permutation.index() method

Permutation.index() : index() is a sympy Python library function that returns the index value of the permutation in argument. Index of a permutation = Sum of all subscripts j such that permutation[j] is greater than permutation[j+1].
Syntax : sympy.combinatorics.permutations.Permutation.index() Return : index value of the permutation
Code #1 : index() Example
 `# Python code explaining ``# SymPy.Permutation.index() `` ` `# importing SymPy libraries ``from` `sympy.combinatorics.partitions ``import` `Partition ``from` `sympy.combinatorics.permutations ``import` `Permutation `` ` `# Using from sympy.combinatorics.permutations.Permutation.index() method  `` ` `# creating Permutation ``a ``=` `Permutation([[``2``, ``0``], [``3``, ``1``]]) `` ` `b ``=` `Permutation([``1``, ``3``, ``5``, ``4``, ``2``, ``0``]) `` ` ` ` `print` `(``"Permutation a - index form : "``, a.index()) ``print` `(``"Permutation b - index form : "``, b.index()) `

Output :
Permutation a – index form : 1 Permutation b – index form : 9
Code #2 : index() Example – 2D Permutation
 `# Python code explaining ``# SymPy.Permutation.index() `` ` `# importing SymPy libraries ``from` `sympy.combinatorics.partitions ``import` `Partition ``from` `sympy.combinatorics.permutations ``import` `Permutation `` ` `# Using from sympy.combinatorics.permutations.Permutation.index() method  `` ` `# creating Permutation ``a ``=` `Permutation([[``2``, ``4``, ``0``],  ``                 ``[``3``, ``1``, ``2``], ``                 ``[``1``, ``5``, ``6``]]) `` ` ` ` `print` `(``"Permutation a - index form : "``, a.index()) `

Output :
Permutation a – index form : 8

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