Method # 1: Using List Comprehension + replace()
The replacement method can be combined with list comprehension techniques to accomplish this particular task. List comprehension performs the task of iterating over the list, and the replace method replaces the substring section with another.

# Python3 demo code # Replace a substring in a list of strings # using a list comprehension + replace ()   # initializing list test_list = [ `4` , `kg` , ` butter` , ` for` , `40` , `bucks` ] < / code>   # print original list print ( "The original list:" + str (test_list))    # using a list comprehension + replace () # Replace a substring in a list of strings res = [sub.replace ( `4` , ` 1` ) for sub in test_list]   # print result  print ( "The list after substring replacement: " + str (res))

Output:

 The original list: [`4` , `kg`,` butter`, `for`,` 40`, `bucks`] The list after substring replacement: [` 1`, `kg`,` butter`, `for`,` 10`, `bucks `] 

Method # 2: Using map () + lambda + replace()
A combination of these functions can also be used to accomplish this specific task. Map and lambda help accomplish the task in the same way as list comprehension, and the replace method is used to perform the replace function. But this method is bad when it comes to performance than the method above.

# Python3 demo code # Replace a substring in a list of strings # using a list comprehension + map () + lambda   # initializing list test_list = [ `4` , `kg` , ` butter` , `for` , ` 40` , `bucks` ]    # print original list print ( "The original list:" + str (test_list))    # using a list comprehension + map () + lambda # Replace a substring in a list of strings res = list ( map ( lambda st: str . replace (st, "4" , "1" ), test_list))    # print result print ( "The list after substring replacement:" + str (res))

Output:

 The original list: [`4`,` kg`, `butter`,` for`, `40`,` bucks`] The list after substring replacement: [`1`,` kg`, `butter`,` for`, `10`,` bucks`]