Python all() Function with Syntax & Examples

The built-in library function all() in Python returns True if all the elements in the passed iterable are true (or if the iterable is empty) else it returns False.

The iterable object (parameter value) can be lists, tuples, dictionaries etc.

all() Syntax

The syntax of all() function is:

all(iterable)

all() Examples

Few examples for Python all() function are:

# one value false, 0 is falsy value
>>> list1 = [0,200,30]
>>> print(all(list1))
False

# all value true
>>>list2 = [5, 10, 15, 20]
>>>print(all(list2))
True

# all value false
>>>list3 = [0, False, 0]
>>>print(all(list3))
False

# empty iterable
>>>list4 = []
>>>print(all(list4))
True

all() Parameters

The all() function takes only one argument. which is:

• iterable - iterable object can be lists, tuples, dictionaries, etc.

all() Return Value

The all(iterable) function returns:

• True — If all elements in an iterable are true or if the iterable is empty.
• False — If any element in an iterable is false.

Programs Using all()

Example 1: Python program for all() using tuple

Program

This program illustrates use of Python all() function with tuples.

tup1 = (5, 1, False)
x = all(tup1)
print(x)

tup2 = ()
print(all(tup2))

mylist = (95,11,12)
x = all(mylist)
print(x)

Output

False
True
True

Example 2: Python program for all() using dictionaries

In 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.

Program

dict1 = {10:  "False" , 100: "False"}
print(all(dict1))

dict2= {0 : “True”, 1: “True”}
print(all(dict2))

dict3 = { }
print(all(dict3))

Output

True
False
True

Example 3: Python program for all() using strings

This program illustrates use of Python all() function with strings.

Program

str1 = "This is test one"
print(all(str1))


# 0 is False
# "0" is True
str2= "0"
print(all(str2))

str3 = ""
print(all(str3))

Output

True
True
True