Python All Function

Last Updated on March 10, 2023 by Abhishek Sharma

As a Python programmer, you will frequently come across Booleans and conditional statements, which may be quite complex. In such scenarios, you should use a function to simplify your reasoning. The Python all function provides all these features. It iterates over an iterable and provides a result indicating if any element in a Boolean context is true. Python all() is a standard method that helps to minimize code length by removing loops. Let us learn about Python all Function in detail.

What is Python All Function?

The Python all function is a built-in function that takes an iterable as an argument and returns True if all the elements in the iterable are true, and False otherwise.

Syntax of the Python All Function

The syntax of the all() function is as follows:

all(iterable)

Parameters of Python All Function

The iterable can be any object that can be looped over, such as a list, tuple, set, or dictionary. It can also be a generator or an iterator.

Return Type of Python All Function

The all() function returns the boolean value in answer:

• True: Python all Function returns True if all the items present in iterable are True.
• False: It returns False if one of the values in the iterable is False.

Usage of the Python All Function

The Python all function is used to check whether all the elements in an iterable are true or not. It is commonly used in conjunction with list comprehension and filter() function to perform complex operations on a list or any other iterable.

Examples of using the Python All Function

Here are some examples of using the all() function in Python.

Example 1: Using Python all Function for Checking whether all the elements in a list are true or not
In this example, we will use the all() function to check whether all the elements in a list are true or not.

Code:

list1 = [True, False, True, True, True]


# Checking if all elements are true
print(all(list1))



list2 = [True, True, True, True, True]


# Checking if all elements are true
print(all(list2))

Output:

False
True

Explanation:
In this example, we have two lists, list1, and list2, containing boolean values. The first list contains a False value, while the second list contains all True values. We use the all() function to check whether all the elements in the lists are true or not. The output of the first list is False, and the output of the second list is True.

Example 2: Using Python all Function with List Comprehension
In this example, we will use the Python all function with a list comprehension to check whether all the elements in a list of lists are true or not.

Code:

# List of lists
list_of_lists = [[True, False, True], [True, True, True], [False, True, True]]

# Using all() function with list comprehension
result = all(all(sub_list) for sub_list in list_of_lists)

# Output
print(result)

Output:

False

Explanation:
In this example, we have a list of lists, list_of_lists, containing boolean values. We use the all() function with a list comprehension to check whether all the elements in the list of lists are true or not. The output of the function is False since the first sub-list contains a False value.

Example 3: Using Python all Function with filter() function
In this example, we will use the Python all function with the filter() function to check whether all the elements in a list are even or not.

Code:

# Using all() function with filter() function


# List of integers
list1 = [2, 4, 6, 8, 10]


# Using all() function with filter() function
even = filter(lambda x: x % 2 == 0, list1)


# Checking if all elements in the filtered list are true
print(all(even))

Output:

True

Explanation:
In the above code, we have a list of integers, list1. We use the filter() function with a lambda function to filter out even numbers from the list. We then use the Python all function to check whether all the elements in the filtered list are true or not. The output of the function is True since all the elements in the filtered list are even.

Example 4: Using Python all Function with dictionary
In this example, we will use the Python all function with a dictionary to check whether all the values in the dictionary are true or not.

Code:

# Using all() function with dictionary


# Dictionary containing boolean values
dict1 = {'a': True, 'b': True, 'c': False, 'd': True}


# Using all() function with dictionary
result = all(dict1.values())


# Output
print(result)

Output:

False

Explanation:
In this example, we have a dictionary, dict1, containing boolean values. We use the values() function to get a list of all the values in the dictionary and then use the Python all function to check whether all the values are true or not. The output of the function is False since the value of the key ‘c’ is False.

Conclusion
In this article, we discussed the all() function in Python. The Python all function is an important built-in function. We also saw some examples of using the all() function with different data structures such as lists, dictionaries, and functions such as list comprehension and filter(). The Python all function is a useful tool for performing complex operations on an iterable in a concise and efficient way.

Frequently Asked Questions (FAQs)

Here are some FAQs on Python all Function.

Ques 1. What is an iterable in Python?
Ans. An iterable in Python is an object that can be looped over. Examples of iterables include lists, tuples, sets, dictionaries, and generators.

Ques 2. What is the difference between the any() and all() functions in Python?
Ans. The any() function returns True if any of the elements in the iterable are true, while the all() function returns True if all the elements in the iterable are true.

Ques 3. Can the Python all function be used with a string?
Ans. Yes, the all() function can be used with a string in Python. When used with a string, it returns True if all the characters in the string are true, and False otherwise.

Ques 4. Can the all() function be used with an empty iterable in Python?
Ans. Yes, the all() function can be used with an empty iterable in Python. When used with an empty iterable, it returns True by default, since there are no false elements in the iterable.

Ques 5. What happens if the all() function is used with a non-iterable in Python?
Ans. If the all() function is used with a non-iterable in Python, a TypeError is raised.