First class objects in a language are handled uniformly throughout. They may be stored in data structures, passed as arguments, or used in control structures. A programming language is said to support first-class functions if it treats functions as first-class objects. Python supports the concept of First Class functions.
Properties of first class functions:
- A function is an instance of the Object type.
- You can store the function in a variable.
- You can pass the function as a parameter to another function.
- You can return the function from a function.
- You can store them in data structures such as hash tables, lists, …
Examples illustrating First Class functions in Python
1. Functions are objects: Python functions are first class objects. In the example below, we are assigning function to a variable. This assignment doesn’t call the function. It takes the function object referenced by shout and creates a second name pointing to it, yell.
2. Functions can be passed as arguments to other functions: Because functions are objects we can pass them as arguments to other functions. Functions that can accept other functions as arguments are also called higher-order functions. In the example below, we have created a function greet which takes a function as an argument.
HI, I AM CREATED BY A FUNCTION PASSED AS AN ARGUMENT. hi, i am created by a function passed as an argument.
3. Functions can return another function: Because functions are objects we can return a function from another function. In the below example, the create_adder function returns adder function.
This article is contributed by Mayank Agrawal. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
- Mathematical Functions in Python | Set 3 (Trigonometric and Angular Functions)
- Mathematical Functions in Python | Set 2 (Logarithmic and Power Functions)
- Mathematical Functions in Python | Set 4 (Special Functions and Constants)
- Mathematical Functions in Python | Set 1 (Numeric Functions)
- Log functions in Python
- Python Inner Functions
- Functions in Python
- Operator Functions in Python | Set 1
- Decimal Functions in Python | Set 1
- Iterator Functions in Python | Set 1
- Operator Functions in Python | Set 2
- Partial Functions in Python
- Python | maketrans() and translate() functions
- Higher Order Functions in Python
- Python | startswith() and endswith() functions