Python filter() function
The filter() function constructs an iterator from those elements of iterable for which the parameter ‘function’ returns a Boolean value true.
Syntax
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filter(function, iterable) |
Parameter
function: This parameter represents a function to be run for each item in the iterable
Iterable: It represents the iterable to be filtered
Return
This function returns an iterator where the items are filtered through a function to test if the item is accepted or not.
Example 1
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#Python program explaining # the filter() function voters_age = [5, 12, 17, 18, 24, 32] def validAge(age): if age < 18: return False else: return True #applying the filter() function adults = filter(validAge, voters_age) for age in adults: print(age) |
Output
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18 24 32 |
Example 2
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#Python program explaining # the filter() function # a list contains both even and odd numbers. values = [10, 11, 12, 13, 15, 18, 103] print("List: ",values) # filter() returning odd numbers of the list even_val = filter(lambda x: x % 2!=0, values) print("Even Values: ",list(even_val)) # filter() returning even numbers of the list odd_val = filter(lambda x: x % 2 == 0, values) print("Odd values: ",list(odd_val)) |
Output
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List: [10, 11, 12, 13, 15, 18, 103] Even Values: [11, 13, 15, 103] Odd values: [10, 12, 18] |