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How to Define and Call a Function in Python

Last Updated : 16 Dec, 2024
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In Python, defining and calling functions is simple and may greatly improve the readability and reusability of our code. In this article, we will explore How we can define and call a function.

Example:

Python 
# Defining a function def fun():     print("Welcome to GFG")      # calling a function    fun()

Let's understand defining and calling a function in detail:

Defining a Function

By using the word def keyword followed by the function's name and parentheses () we can define a function. If the function takes any arguments, they are included inside the parentheses. The code inside a function must be indented after the colon to indicate it belongs to that function.

Syntax of defining a function:

def function_name(parameters):

# Code to be executed

return value

  • function_name: The name of your function.
  • parameters: Optional. A list of parameters (input values) for the function.
  • return: Optional. The return statement is used to send a result back from the function.

Example:

Python 
def fun():     print("Welcome to GFG")      # Defining a function with parameters     def greet(name, age):      print(name, age)

Explanation:

  • fun(): A simple function that prints "Welcome to GFG" when called, without any parameters.
  • greet(name, age): A function with two parameters (name and age) that prints the values passed to it when called.

Calling a Function

To call a function in Python, we definitely type the name of the function observed via parentheses (). If the function takes any arguments, they may be covered within the parentheses . Below is the example for calling def function Python.

Syntax of Calling a function:

function_name(arguments)

Example:

Python 
def fun():     print("Welcome to GFG") #calling a function  fun()      # Defining a function with parameters     def greet(name, age):      print(name, age)      #calling a function by passing arguments greet("Alice",21)

Output
Welcome to GFG Alice 21

Explanation:

  • Calling fun(): The function fun() is called without any arguments, and it prints "Welcome to GFG".
  • Calling greet("Alice", 21): The function greet() is called with the arguments "Alice" and 21, which are printed as "Alice 21".

Next Article
How to Add Function in Python Dictionary

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Article Tags :
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  • python
Practice Tags :
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