Python - Random Replacement of Word in String

Last Updated : 13 Mar, 2023

Given a string and List, replace each occurrence of K word in string with random element from list.

Input : test_str = "Gfg is x. Its also x for geeks", repl_list = ["Good", "Better", "Best"], repl_word = "x" Output : Gfg is Best. Its also Better for geeks Explanation : x is replaced by random replace list values. Input : test_str = "Gfg is x. Its also x for geeks", repl_list = ["Good", "Better", "Nice"], repl_word = "x" Output : Gfg is Best. Its also Nice for geeks Explanation : x is replaced by random replace list values, "Best" and "Nice".

Method #1 : Using shuffle() + loop + replace()

The combination of above functions can be used to solve this problem. In this, we replace each occurrence of K word with random string from list using replace().

Python3

# Python3 code to demonstrate working of 
# Random Replacement of Word in String
# Using replace() + shuffle() + loop
from random import shuffle

# initializing string
test_str = "Gfg is val. Its also val for geeks"

# printing original string
print("The original string is : " + str(test_str))

# initializing list 
repl_list = ["Good", "Better", "Best"]

# initializing replace word
repl_word = "val"

# shuffing list order
shuffle(repl_list)
for ele in repl_list:
    
    # replacing with random string 
    test_str = test_str.replace(repl_word, ele, 1)
    
# printing result 
print("String after random replacement : " + str(test_str))

Output

The original string is : Gfg is val. Its also val for geeks
String after random replacement : Gfg is Best. Its also Better for geeks

Time Complexity: O(n*n) where n is the number of elements in the list “test_list”.
Auxiliary Space: O(n) where n is the number of elements in the list “test_list”.

Method #2 : Using list comprehension + replace() + shuffle()

This is one of the ways in which this task can be performed. In this, we encapsulate entire logic in one-liner using similar functionalities as above method.

Python3

# Python3 code to demonstrate working of 
# Random Replacement of Word in String
# Using list comprehension + replace() + shuffle()
from random import shuffle

# initializing string
test_str = "Gfg is val. Its also val for geeks"

# printing original string
print("The original string is : " + str(test_str))

# initializing list 
repl_list = ["Good", "Better", "Best"]

# initializing replace word
repl_word = "val"

# one-liner to solve problem
shuffle(repl_list)
res = [test_str.replace(repl_word, ele, 1) for ele in repl_list]
    
# printing result 
print("String after random replacement : " + str(res))

Output

The original string is : Gfg is val. Its also val for geeks String after random replacement : ['Gfg is Good. Its also val for geeks', 'Gfg is Better. Its also val for geeks', 'Gfg is Best. Its also val for geeks']

The Time and Space Complexity for all the methods are the same:

Time Complexity: O(n)

Space Complexity: O(n)