Python | SymPy combinatorics.prev_lex() method

With the help of sympy.combinatorics.partitions.IntegerPartition().prev_lex() method, we can get the previous partition of integer n in lexical order by using sympy.combinatorics.partitions.IntegerPartition().prev_lex() method.

Syntax : sympy.combinatorics.partitions.IntegerPartition().prev_lex()
Return : Return the lexical value of previous partition of integer n.

Example #1 :
In this example we can see that by using sympy.combinatorics.partitions.IntegerPartition().prev_lex() method, we are able to get the lexical value of previous partition of integer n.

# import sympy and IntegerPartition
from sympy.combinatorics.partitions import IntegerPartition
from sympy import *

# Using sympy.combinatorics.partitions.IntegerPartition().prev_lex() method
gfg = IntegerPartition([1, 2, 3])

print(gfg.prev_lex())

Output :

[3, 1, 1, 1]

Example #2 :

# import sympy and IntegerPartition
from sympy.combinatorics.partitions import IntegerPartition
from sympy import *

# Using sympy.combinatorics.partitions.IntegerPartition().prev_lex() method
gfg = IntegerPartition([1, 2, 3, 4, 3, 2, 1])

print(gfg.prev_lex())

Output :

[4, 3, 3, 2, 1, 1, 1, 1]