# SymPy | Subset.prev_binary() in Python

• Last Updated : 28 Aug, 2019

Subset.prev_binary() : prev_binary() is a sympy Python library function that returns the previous binary ordered subset.

Syntax :
sympy.combinatorics.subset.Subset.prev_binary()

Return :
the previous binary ordered subset.

Code #1 : prev_binary() Example

 `# Python code explaining``# SymPy.Subset.prev_binary()`` ` `# importing SymPy libraries``from` `sympy.combinatorics ``import` `Permutation, Cycle``from` `sympy.combinatorics.subsets ``import` `Subset`` ` `# Using from ``# sympy.combinatorics.subset.Subsets.prev_binary()`` ` `# Creating Subset``a ``=` `Subset([``'c'``, ``'d'``], [``'geek'``, ``'for'``, ``'c'``, ``'d'``])`` ` `# prev_binary value``print` `(``"Subset a prev_binary : "``, a.prev_binary().subset)`

Output :

Subset a prev_binary : [‘c’]

Code #2 : prev_binary() Example

 `# Python code explaining``# SymPy.Subset.prev_binary()`` ` `# importing SymPy libraries``from` `sympy.combinatorics ``import` `Permutation, Cycle``from` `sympy.combinatorics.subsets ``import` `Subset`` ` `# Using from ``# sympy.combinatorics.subset.Subsets.prev_binary()`` ` `# Creating Subset``a ``=` `Subset([``'k'``, ``'a'``], [``'23'``, ``'k'``, ``'a'``])`` ` `# prev_binary value``print` `(``"Subset a prev_binary : "``, a.prev_binary().subset)`

Output :

Subset a prev_binary : [‘k’]

My Personal Notes arrow_drop_up