How to use Python filter()
Python provides 3 useful global functions we can use to work with collections: map(), filter() and reduce().
Tip: sometimes list comprehensions make more sense and are generally considered more pythonic
filter() takes an iterable and returns a filter object, which is another iterable, but without some of the original items.
You do so by returning True or False from the filtering function:
numbers = [1, 2, 3]
def isEven(n):
return n % 2 == 0
result = filter(isEven, numbers)
print(list(result)) # [2]You can use a lambda function to make the code more concise:
numbers = [1, 2, 3]
result = filter(lambda n: n % 2 == 0, numbers)
print(list(result)) # [2]download all my books for free
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