Clearing a list is a common problem and solution to it has been discussed many times. But sometimes, we don’t have a native list but list is a value to dictionary key. Clearing it is not as easy as clearing an original list. Let’s discuss certain ways in which this can be done.
Method #1 : Using loop + clear()
This is the most generic method in which we can perform this particular function. We just run a loop till the last dictionary key and clear the key’s list value as they occur using clear function.
# Python3 code to demonstrate # clearing list as dict. value # using loop + clear() # initializing dict. test_dict = {"Akash" : [1, 4, 3], "Nikhil" : [3, 4, 1], "Akshat" : [7, 8]} # printing original dict print("The original dict : " + str(test_dict)) # using loop + clear() # clearing list as dict. value for key in test_dict: test_dict[key].clear() # print result print("The dictionary after clearing value list : " + str(test_dict)) |
The original dict : {‘Nikhil’: [3, 4, 1], ‘Akshat’: [7, 8], ‘Akash’: [1, 4, 3]}
The dictionary after clearing value list : {‘Nikhil’: [], ‘Akshat’: [], ‘Akash’: []}
Method #2 : Using dictionary comprehension
We can reduce the lines of code and merge the above functionality using just the dictionary comprehension and clearing the list using the list re-initialization.
# Python3 code to demonstrate # clearing list as dict. value # using dictionary comprehension # initializing dict. test_dict = {"Akash" : [1, 4, 3], "Nikhil" : [3, 4, 1], "Akshat" : [7, 8]} # printing original dict print("The original dict : " + str(test_dict)) # using dictionary comprehension # clearing list as dict. value test_dict = {key : [] for key in test_dict} # print result print("The dictionary after clearing value list : " + str(test_dict)) |
The original dict : {‘Nikhil’: [3, 4, 1], ‘Akshat’: [7, 8], ‘Akash’: [1, 4, 3]}
The dictionary after clearing value list : {‘Nikhil’: [], ‘Akshat’: [], ‘Akash’: []}
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