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# Python2.x Python filter() Function [ Python Built-in Functions](#) * * * ## Description The **filter()** function is used to filter a sequence, removing elements that do not meet the conditions, and returns a new list composed of elements that meet the conditions. It takes two arguments: the first is a function, and the second is a sequence. Each element of the sequence is passed as an argument to the function for evaluation, which then returns True or False. Finally, the elements that returned True are placed into a new list. > **Note:** Python2.7 returns a list, while Python3.x returns an iterator object. For more details, see: [Python3 filter() Function](#) ### Syntax The syntax for the filter() method is: filter(function, iterable) ### Parameters * function -- The judgment function. * iterable -- An iterable object. ### Return Value Returns a list. * * * ## Examples The following examples demonstrate the use of the filter function: ## Filter out all odd numbers from a list: #!/usr/bin/python# -*- coding: UTF-8 -*-def is_odd(n): return n % 2 == 1 newlist = filter(is_odd, [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])print(newlist) Output: [1, 3, 5, 7, 9] ## Filter out numbers between 1 and 100 whose square root is an integer: #!/usr/bin/python# -*- coding: UTF-8 -*-import math def is_sqr(x): return math.sqrt(x) % 1 == 0 newlist = filter(is_sqr, range(1, 101))print(newlist) Output: [1, 4, 9, 16, 25, 36, 49, 64, 81, 100] [ Python Built-in Functions](#)