Python – Random Replacement of Word in String

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 Beginner”, repl_list = [“Good”, “Better”, “Best”], repl_word = “x” Output : Gfg is Best. Its also Better for Beginner Explanation : x is replaced by random replace list values. Input : test_str = “Gfg is x. Its also x for Beginner”, repl_list = [“Good”, “Better”, “Nice”], repl_word = “x” Output : Gfg is Best. Its also Nice for Beginner 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 Beginner"
 
# 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 Beginner
String after random replacement : Gfg is Best. Its also Better for Beginner

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 Beginner"
 
# 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 Beginner String after random replacement : [‘Gfg is Good. Its also val for Beginner’, ‘Gfg is Better. Its also val for Beginner’, ‘Gfg is Best. Its also val for Beginner’]

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

Time Complexity: O(n)

Space Complexity: O(n)