Python – Test if a list is completely True

Sometimes, we need to check if a list is completely True, 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
# Pure List Test
# using naive method

# initializing list
test_list = [True, True, True, True]

# printing original list
print ("The original list is : " + str(test_list))

flag = 0

# using naive method
# Pure List Test
for i in test_list :
    if not i :
        flag = 1
        break

# printing result
print ("Is List completely True ? : " + str(bool(not flag)))

Output :

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

Method #2 : Using all()
This function tests each value to be True and if yes, returns boolean True, else returns false. The list iteration is done using list comprehension.

# Python3 code to demonstrate
# Pure List Test
# using all()

# initializing list
test_list = [True, True, True, True]

# printing original list
print ("The original list is : " + str(test_list))

flag = 0

# using all()
# Pure List Test
res = all(i for i in test_list)

# printing result
print ("Is List completely True ? : " + str(res))

Output :

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