all() is a built-in function in Python 3 (and Python 2 since version 2.5), to check if all items of an iterable are True . It takes one argument, iterable .
Argument
iterable
The iterable argument is the collection whose entries are to be checked. It can be a list , str , dict , tuple , etc.
Return Value
The return value is a Boolean. If and only if all entries of iterable are truthy, it returns True . This function essentially performs a Boolean AND operation over all elements.
If even one of them is not truthy, it returns False .
The all() operation is equivalent to (not internally implemented exactly like this)
def all(iterable):
for element in iterable:
if not element:
return False
return True
Code Sample
print(all([])) #=> True # Because an empty iterable has no non-truthy elements
print(all([6, 7])) #=> True
print(all([6, 7, None])) #=> False # Because it has None
print(all([0, 6, 7])) #=> False # Because it has zero
print(all([9, 8, [1, 2]])) #=> True
print(all([9, 8, []])) #=> False # Because it has []
print(all([9, 8, [1, 2, []]])) #=> True
print(all([9, 8, {}])) #=> False # Because it has {}
print(all([9, 8, {'engine': 'Gcloud'}])) #=> True
