Python program to get all possible slices of a string for K number of slices

Last Updated : 09 May, 2021

Given a string, the task is to write a Python program to get all possible slices for K number of slices.

Input : test_str = “Gfg4all”, K = 3
Output : [[‘G’, ‘f’, ‘g4all’], [‘G’, ‘fg’, ‘4all’], [‘G’, ‘fg4’, ‘all’], [‘G’, ‘fg4a’, ‘ll’], [‘G’, ‘fg4al’, ‘l’], [‘Gf’, ‘g’, ‘4all’], [‘Gf’, ‘g4’, ‘all’], [‘Gf’, ‘g4a’, ‘ll’], [‘Gf’, ‘g4al’, ‘l’], [‘Gfg’, ‘4’, ‘all’], [‘Gfg’, ‘4a’, ‘ll’], [‘Gfg’, ‘4al’, ‘l’], [‘Gfg4’, ‘a’, ‘ll’], [‘Gfg4’, ‘al’, ‘l’], [‘Gfg4a’, ‘l’, ‘l’]]
Explanation : All possible 3 slices for constructing string are returned.
Input : test_str = “Gfg4all”, K = 2

Output : [[‘G’, ‘fg4all’], [‘Gf’, ‘g4all’], [‘Gfg’, ‘4all’], [‘Gfg4’, ‘all’], [‘Gfg4a’, ‘ll’], [‘Gfg4al’, ‘l’]]
Explanation : All possible 2 slices for constructing string are returned.

Method #1 : Using list comprehension + slicing + loop

In this, consecutive slices are computed incrementally starting from size 1. The last element is always split into 2 in all the ways in acc. to other strings.

Python3

# Python3 code to demonstrate working of
# All possible slices for K length
# Using list comprehension + string slicing + loop
  
# initializing string
test_str = "Gfg4all"
  
# printing original string
print("The original string is : " + str(test_str))
  
# initializing number of slices
K = 3
  
res = [[test_str]]
for idx in range(K - 1):
  
    # slicing initial strings with difference sizes.
    res = [[*strt, end[:y], end[y:]] for *strt, end in res
           for y in range(1, len(end) - K + idx + 2)]
  
# printing result
print("All possible slices for K strings : " + str(res))

Output:

The original string is : Gfg4all
All possible slices for K strings : [[‘G’, ‘f’, ‘g4all’], [‘G’, ‘fg’, ‘4all’], [‘G’, ‘fg4’, ‘all’], [‘G’, ‘fg4a’, ‘ll’], [‘G’, ‘fg4al’, ‘l’], [‘Gf’, ‘g’, ‘4all’], [‘Gf’, ‘g4’, ‘all’], [‘Gf’, ‘g4a’, ‘ll’], [‘Gf’, ‘g4al’, ‘l’], [‘Gfg’, ‘4’, ‘all’], [‘Gfg’, ‘4a’, ‘ll’], [‘Gfg’, ‘4al’, ‘l’], [‘Gfg4’, ‘a’, ‘ll’], [‘Gfg4’, ‘al’, ‘l’], [‘Gfg4a’, ‘l’, ‘l’]]

Method #2 : Using combinations() + zip() + list comprehension

In this, combinations is used to get all possible substrings for the ranges computed using slicing during iteration.

Python3

# Python3 code to demonstrate working of
# All possible slices for K length
# Using combinations() + zip() + list comprehension
from itertools import combinations
  
# initializing string
test_str = "Gfg4all"
  
# printing original string
print("The original string is : " + str(test_str))
  
# initializing number of slices
K = 3
  
# combinations used to perform all possible slices
res = [[test_str[idx: j] for idx, j in zip([None, *sub], [*sub, None])]
       for sub in combinations(range(1, len(test_str)), K - 1)]
  
# printing result
print("All possible slices for K strings : " + str(res))

Output:

The original string is : Gfg4all
All possible slices for K strings : [[‘G’, ‘f’, ‘g4all’], [‘G’, ‘fg’, ‘4all’], [‘G’, ‘fg4’, ‘all’], [‘G’, ‘fg4a’, ‘ll’], [‘G’, ‘fg4al’, ‘l’], [‘Gf’, ‘g’, ‘4all’], [‘Gf’, ‘g4’, ‘all’], [‘Gf’, ‘g4a’, ‘ll’], [‘Gf’, ‘g4al’, ‘l’], [‘Gfg’, ‘4’, ‘all’], [‘Gfg’, ‘4a’, ‘ll’], [‘Gfg’, ‘4al’, ‘l’], [‘Gfg4’, ‘a’, ‘ll’], [‘Gfg4’, ‘al’, ‘l’], [‘Gfg4a’, ‘l’, ‘l’]]

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