Remove falsy values from a list in Python

Removing falsy values from a list filters out unwanted values like None, False, 0 and empty strings, leaving only truthy values. It's useful for data cleaning and validation.

Using List Comprehension

List comprehension is a fast and efficient way to remove falsy values from a list . It filters out values like 0, None, False and empty strings, creating a new list with only truthy values.

Example:

a = [[], (), "GeeksForGeeks", 26, 27]
res = [x for x in a if x]  # Remove falsy values
print(res)

['GeeksForGeeks', 26, 27]

Let's explore more methods to remove falsy values from a list in Python.

Using filter()

filter() function removes falsy values by using None as the filtering function. It filters out any item that evaluates to False, creating a new list with truthy values.

Example:

a= [0, 1, '', 2, None, 3, False, 4]
res= list(filter(None,a)) # Remove falsy values
print(res)

[1, 2, 3, 4]

Using itertools.filterfalse()

itertools.filterfalse() function removes falsy values by filtering out items that evaluate to False. It is an efficient way to keep only truthy values in list.

Example:

from itertools import filterfalse
a= [0, 1, '', 2, None, 3, False, 4]
# Remove falsy values
res= list(filterfalse(lambda x: not x,a))
print(res)

[1, 2, 3, 4]