Sometimes, we need to check if a list is completely True of False, these occurrences come more often in testing purposes after the development phase. Hence, having a knowledge of all this is necessary and useful. Lets discuss certain ways in which this can be performed.
Method #1 : Naive Method
In the naive method, we just run a loop from beg to end of list and check manually for each value. This is the most basic way to perform this particular task.
# Python3 code to demonstrate # to check for False list # using naive method # initializing list test_list = [False, False, False, False] # printing original list print ("The original list is : " + str(test_list)) flag = 0 # using naive method # to check for False list for i in test_list : if i == True : flag = 1 break # printing result print ("Is List completely false ? : " + str(bool(not flag))) |
The original list is : [False, False, False, False] Is List completely false ? : True
Method #2 : Using all()
This function tests each value to be False and if yes, returns boolean True, else returns false. The list iteration is done using list comprehension.
# Python3 code to demonstrate # to check for False list # using all() # initializing list test_list = [False, False, False, False] # printing original list print ("The original list is : " + str(test_list)) flag = 0 # using all() # to check for False list res = all(not i for i in test_list) # printing result print ("Is List completely false ? : " + str(res)) |
The original list is : [False, False, False, False] Is List completely false ? : True
Method #3 : Using any()
This function tests for any one of the True value, if found returns True, else returns False value. Negation of this function is used as the result.
# Python3 code to demonstrate # to check for False list # using any() # initializing list test_list = [False, False, False, False] # printing original list print ("The original list is : " + str(test_list)) # using any() # to check for False list res = not any(test_list) # printing result print ("Is List completely false ? : " + str(res)) |
The original list is : [False, False, False, False] Is List completely false ? : True
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