Given a List. The task is to replace all the characters of the list with N except the given character.
Input : test_list = [‘G’, ‘F’, ‘G’, ‘I’, ‘S’, ‘B’, ‘E’, ‘S’, ‘T’], repl_chr = ‘*’, ret_chr = ‘G’
Output : [‘G’, ‘*’, ‘G’, ‘*’, ‘*’, ‘*’, ‘*’, ‘*’, ‘*’]
Explanation : All characters except G replaced by *Input : test_list = [‘G’, ‘F’, ‘G’, ‘B’, ‘E’, ‘S’, ‘T’], repl_chr = ‘*’, ret_chr = ‘G’
Output : [‘G’, ‘*’, ‘G’, ‘*’, ‘*’, ‘*’, ‘*’]
Explanation : All characters except G replaced by *
Method #1 : Using list comprehension + conditional expressions
In this, we perform the task of iteration using list comprehension, and replacements are taken care of using conditional operators.
Python3
# Python3 code to demonstrate working of # Replace all Characters Except K # Using list comprehension and conditional expressions # initializing lists test_list = [ 'G' , 'F' , 'G' , 'I' , 'S' , 'B' , 'E' , 'S' , 'T' ] # printing original list print ( "The original list : " + str (test_list)) # initializing repl_chr repl_chr = '$' # initializing retain chararter ret_chr = 'G' # list comprehension to remake list after replacement res = [ele if ele = = ret_chr else repl_chr for ele in test_list] # printing result print ( "List after replacement : " + str (res)) |
The original list : ['G', 'F', 'G', 'I', 'S', 'B', 'E', 'S', 'T'] List after replacement : ['G', '$', 'G', '$', '$', '$', '$', '$', '$']
Method #2 : Using map() + lambda
In this, we use map() and lambda function to extend the logic to each element of the list.
Python3
# Python3 code to demonstrate working of # Replace all Characters Except K # Using map() + lambda # initializing lists test_list = [ 'G' , 'F' , 'G' , 'I' , 'S' , 'B' , 'E' , 'S' , 'T' ] # printing original list print ( "The original list : " + str (test_list)) # initializing repl_chr repl_chr = '$' # initializing retain chararter ret_chr = 'G' # using map() to extend logic to each element of list res = list ( map ( lambda ele: ret_chr if ele = = ret_chr else repl_chr, test_list)) # printing result print ( "List after replacement : " + str (res)) |
The original list : ['G', 'F', 'G', 'I', 'S', 'B', 'E', 'S', 'T'] List after replacement : ['G', '$', 'G', '$', '$', '$', '$', '$', '$']
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