The all() function returns True if all elements in the given iterable are truthy. If not, it returns False.
Example
boolean_list = ['True', 'True', 'True']
# check if all elements are true
result = all(boolean_list)
print(result)
# Output: True
all() Syntax
The syntax of the all() function is:
all(iterable)
all() Parameters
The all() function takes a single parameter:
- iterable - any iterable (list, tuple, dictionary, etc.) which contains the elements
all() Return Value
all() function returns:
- True - If all elements in an iterable are true
- False - If any element in an iterable is false
| When | Return Value |
|---|---|
| All values are true | True |
| All values are false | False |
| One value is true (others are false) | False |
| One value is false (others are true) | False |
| Empty Iterable | True |
Note: Truthy values include non-zero numbers, non-empty sequences, and True. Falsy values include 0, None, False, and empty sequences.
Example 1: How all() works for lists?
# all values true
l = [1, 3, 4, 5]
print(all(l))
# all values false
l = [0, False]
print(all(l))
# one false value
l = [1, 3, 4, 0]
print(all(l))
# one true value
l = [0, False, 5]
print(all(l))
# empty iterable
l = []
print(all(l))
Output
True False False False True
The all() function works in a similar way for tuples and sets like lists.
Example 2: How all() works for strings?
s = "This is good"
print(all(s))
# 0 is False
# '0' is True
s = '000'
print(all(s))
s = ''
print(all(s))
Output
True True True
Example 3: How all() works with Python dictionaries?
In the case of dictionaries, if all keys (not values) are true or the dictionary is empty, all() returns True. Else, it returns false for all other cases..
s = {0: 'False', 1: 'False'}
print(all(s))
s = {1: 'True', 2: 'True'}
print(all(s))
s = {1: 'True', False: 0}
print(all(s))
s = {}
print(all(s))
# 0 is False
# '0' is True
s = {'0': 'True'}
print(all(s))
Output
False True False True True
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