Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from https://www.tutorialspoint.com/python/python_itertools_filterfalse_function.htm below:

Python itertools.filterfalse() Function

The Python itertools.filterfalse() function is used to filter elements from an iterable by removing those that satisfy a given predicate function. It returns only those elements for which the predicate evaluates to False.

This function is useful when you need to exclude specific elements based on a condition.

Following is the syntax of the Python itertools.filterfalse() function −

itertools.filterfalse(predicate, iterable)

This function accepts the following parameters −

• predicate: A function that returns True or False. Elements are included only if the function returns False.
• iterable: The iterable to be processed.

This function returns an iterator containing elements from iterable where predicate evaluates to False.

Following is an example of the Python itertools.filterfalse() function. Here, we remove even numbers from the list −

import itertools

def is_even(n):
   return n % 2 == 0

numbers = [1, 2, 3, 4, 5, 6, 7, 8]
result = itertools.filterfalse(is_even, numbers)
for num in result:
   print(num)

Following is the output of the above code −

1
3
5
7

Here, we use itertools.filterfalse() function to filter out words that start with an uppercase letter −

import itertools

def starts_with_upper(s):
   return s[0].isupper()

words = ["apple", "Banana", "cherry", "Date", "elderberry"]
filtered_words = itertools.filterfalse(starts_with_upper, words)
for word in filtered_words:
   print(word)

Output of the above code is as follows −

apple
cherry
elderberry

Now, we use itertools.filterfalse() function to remove tuples where the first element is negative −

import itertools

def is_negative(t):
   return t[0] < 0

data = [(-2, "A"), (-1, "B"), (0, "C"), (1, "D"), (2, "E")]
result = itertools.filterfalse(is_negative, data)
for item in result:
   print(item)

The result obtained is as shown below −

(0, "C")
(1, "D")
(2, "E")

We can use itertools.filterfalse() function to remove empty strings from a list of words −

import itertools

def is_empty(s):
   return s == ""

words = ["hello", "", "world", "", "python", ""]
filtered_words = itertools.filterfalse(is_empty, words)
for word in filtered_words:
   print(word)

The result produced is as follows −

hello
world
python

python_modules.htm

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4