# all() function in Python

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## Introduction

The `all()` function returns `True` if all elements in the given iterable are true. If not, it returns `False`.

The `all()` function takes a single parameter `iterable` and returns `True` if all elements in an iterable are true or `False` if any element in an iterable is false.

The syntax of the `all()` function is:

``````all(iterable)
``````

where iterable can be any iterable (list, tuple, dictionary, etc.) which contains the elements.

Since `all()` can return True and False depending upon the conditions, we can summarise its return value in the following table:

 Condition Return Value All values are `True` `True` All values are `False` `False` One of the values in `True` (others are `False`) `False` One of the values is `False` (others are `True`) `False` Empty Iterable `True`

## Working of `all()` for lists, tuples, and sets

``````## All values are true
list1 = [1, 2, 3, 4, 5]
print(all(list1))

## All values are false
list2 = [0, False]
print(all(list2))

## One value is false(i.e. 0)
list3 = [1, 2, 3, 4, 0]
print(all(list3))

## One value is true(i.e. 1)
list4 = [0, False, 1]
print(all(list4))

## Empty iterable
list5 = []
print(all(list5))
``````

Output:

``````True
False
False
False
True
``````

## Working of `all()` for strings

``````string1 = "I am learning Python built-ins"
print(all(string1))

## 0 is False but '0' is True
string2 = '00000'
print(all(string2))

## Empty String
string3 = ''
print(all(string3))
``````

Output:

``````True
True
True
``````

## Working of `all()` for dictionaries

``````## O is False
dict1 = {0: 'False', 1: 'True'}
print(all(dict1))

## All values are true
dict2 = {1: 'True', 2: 'True'}
print(all(dict2))

## One value is False
dict3 = {1: 'True', False: 0}
print(all(dict3))

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

## 0 is False but '0' is True
dict5 = {'0': 'False'}
print(all(dict5))
``````

Output:

``````False
True
False
True
True
``````

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.

Note: 0 is considered as False and 1 is considered as True in Python. In addition to that, '0' is True whereas 0 is False.

## Conclusion

In this part, we learned about the Python `all()` function with the help of examples.