Python all() Function

The python all() function accepts an iterable object (such as list,dictionary etc.). It returns True if all items in passed iterable are true, otherwise it returns False. If the iterable object is empty, the all() function returns True.

Signature

Parameters

iterable - The objects which contain the elements i.e. list, tuple and dictionary, etc.

Return

True - If all the elements in an iterable are true.
False - If all the elements in an iterable are false..

Python all() Function Example 1

Let's see how all() works for lists?

# all values true
k = [1, 3, 4, 5]
print(all(k))

# all values false
k = [0, False]
print(all(k))

# one false value
k = [1, 3, 4, 0]
print(all(k))

# one true value
k = [0, False, 5]
print(all(k))

# empty iterable
k = []
print(all(k))

Output:

True
False
False
False
True

Python all() Function Example 2

The below example shows how all() works for dictionaries.

# Both the keys are true
dict1 = {1: 'True', 2: 'False'}
print(all(dict1))

# One of the key is false
dict2 = {0: 'True', 1: 'True'}
print(all(dict2))

# Both the keys are false
dict3 = {0: 'True', False: 0}
print(all(dict3))

# Empty dictionary
dict4 = {}
print(all(dict4))

# Here the key is actually true because
#  0 is non-null string rather than a zero
dict5 = {'0': 'True'}
print(all(dict5))

Output:

True
False 
False 
True 
True

Python all() Function Example 3

The below example shows how all() works for tuples.

# all true values
t1 = (1, 2, 3, 4, 5)
print(all(t1))

# one false value
t2 = (0, 1, "Hello")
print(all(t2))

# all false values
t3 = (0, False , 0)
print(all(t3))

# one true value, all false
t4 = (True, 0, False)
print(all(t4))

Output: