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HomeBackend DevelopmentPython TutorialHow to remove null values ​​from a list in Python

How to remove null values ​​from a list in Python

Mar 02, 2024 am 08:56 AM
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How to remove null values ​​from a list in Python

To remove null values ​​​​in the list, you can use list comprehensions or the filter() function.

Method 1: Use list comprehensions You can use list comprehensions to create a new list while filtering out null values ​​in the list.

original_list = [1, 2, None, 3, '', 4, ' ', 5]
new_list = [x for x in original_list if x is not None and x != '']
print(new_list)

Output result:

[1, 2, 3, 4, 5]

Method 2: Use filter() function You can use the filter() function to filter out null values ​​​​in the list and convert the returned results into a list.

original_list = [1, 2, None, 3, '', 4, ' ', 5]
new_list = list(filter(lambda x: x is not None and x != '', original_list))
print(new_list)

Output result:

[1, 2, 3, 4, 5]

No matter which method is used, the null values ​​​​in the list can be filtered out and a new list can be obtained.

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