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# Python | SymPy Permutation.descents () Method

Permutation.descents (): descents () — nice Python library function that returns the descent position in a permutation. Slopes — these are elements where a [i] & gt; a [i + 1]

Syntax: sympy.combinatorics.permutations.Permutation.descents ()

Return: position of descents in the permutation

Code # 1: example descents ()

 ` # Python code explaining ` ` # SymPy.descents () `   ` # import SymPy libraries ` ` from ` ` sympy.combinatorics.partitions ` ` import ` ` Partition ` ` from ` ` sympy.combinatorics.permutations ` ` import ` ` Permutation `   ` # Using meta ode sympy.combinatorics.permutations.Permutation.descents () `   ` # create permutations ` ` a ` ` = ` ` Permutation ([[ ` ` 2 ` `, ` ` 0 ` `], [` ` 3 ` `, ` ` 1 ` `]]) `   ` b ` ` = ` ` Permutation ([` ` 1 ` `, ` ` 3 ` `, ` ` 5 ` `, ` ` 4 ` `, ` ` 2 ` `, ` ` 0 ` `]) `     ` print ` ` (` ` "Permutation a - descents form:" ` `, a.descents ()) ` ` print ` ` (` ` "Permutation b - descents form:" ` `, b.descents ()) `

Output:

Permutation a - descents form: [1]
Permutation b - descents form: [2, 3, 4]

Code # 2: example descents () — 2D permutation

 ` # Python code explaining ` ` # SymPy.descents () ``   # import SymPy libraries from sympy.combinatorics.partitions import Partition from sympy.combinatorics.permutations import Permutation   # Using the sympy.combinatorics.permutations.Permutation.descents () method   # create permutation `` a = ` ` Permutation ([[` ` 2 ` `, ` ` 4 ` `, ` ` 0 ` `], ` ` [` ` 3 ` `, ` ` 1 ` `, ` ` 2 ` `], ` ` [` ` 1 ` `, ` ` 5 ` `, ` ` 6 ` `]]) `     ` print ` ` (` ` "Permutation a - descents form:" ` `, a.descents ()) `` `

Output:

Permutation a - descents form: [0, 3, 5]