# Python | Clearing list as dictionary value

• Last Updated : 29 Mar, 2019

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.

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 `# 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))`
Output :

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))`
Output :

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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