This tutorial will discuss about unique ways to check if all elements in list are false in Python.
Table Of Contents
Technique 1: Using all() method
Using the all() method, we can confirm if a sequence contains all True
values. Now, to check if a list has all False
values, we can invert the values in List and check if all the values are True or not using all() method. For example, this expression will return ‘True’ if list has all False
values,
all(not elem for elem in listOfElements)
Now we can use this to check if all elements in a given list are False
or not.
Let’s see the complete example,
# Example 1 listOfElements = [False, False, False, False] # check if all elements in list are False if all(not elem for elem in listOfElements): print("Yes, All elements in list are False") else: print("No, All elements in list are not False") # Example 2 listOfElements = [False, True, False, False] # check if all elements in list are False if all(not elem for elem in listOfElements): print("Yes, All elements in list are False") else: print("No, All elements in list are not False")
Output
Yes, All elements in list are False No, All elements in list are not False
Technique 2: Using for-loop
Iterate over all the elements of List using a for loop. During iteration, for each element check if it is True
or not. As soon as a True
element is encountered, break the loop, and mark that list does not have all False
values. We have created a function for this,
Frequently Asked:
def is_all_false(listObj): '''Returns True if all elements in list are False''' result = True for elem in listObj: if elem: result = False break return result
This function accepts a list as argument, and returns True
, if all the elements in this list are False
. In this function, we will loop through all the values of list, and will look any non False value.
Let’s see the complete example,
def is_all_false(listObj): '''Returns True if all elements in list are False''' result = True for elem in listObj: if elem: result = False break return result # Example 1 listOfElements = [False, False, False, False] # check if all elements in list are False if is_all_false(listOfElements): print("Yes, All elements in list are False") else: print("No, All elements in list are not False") # Example 2 listOfElements = [False, True, False, False] # check if all elements in list are False if is_all_false(listOfElements): print("Yes, All elements in list are False") else: print("No, All elements in list are not False")
Output
Yes, All elements in list are False No, All elements in list are not False
Summary
We learned about two different ways to check if a List contains all False values or not. Thanks.