If the function parameter is None
, then the identity function will be used:
list(filter(None, [1, 0, 2, [], '', 'a'])) # discards 0, [] and ''
# Out: [1, 2, 'a']
[i for i in [1, 0, 2, [], '', 'a'] if i] # equivalent list comprehension
(i for i in [1, 0, 2, [], '', 'a'] if i) # equivalent generator expression