Python | Test for False list

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)))

Output:

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))

Output:

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))

Output:

The original list is : [False, False, False, False]
Is List completely false ? : True