Functions in Python

Python : Functions

A function is a block of code that performs a specific task and can be reused multiple times in a program.

How to create a function in Python?

In Python, functions are defined using the def keyword, followed by the function name, parameters(Arguments) in parentheses, and a colon.

Function's Syntax in Python

# Function definition
def function_name(...parameters):
    # function_body(function definitions)
    # It can't be empty

# Calling a Function
function_name(...parameters)

How to paas Arguments(parameters) to Function

Information can be passed into functions as arguments(also called parameters).

• Argument With Default Value

  def greet(name, greeting='Hello'):
      print(greeting + ', ' + name)
  
  greet('John') # Output: Hello, John
  greet('Jane', 'Hi') # Output: Hi, Jane
  
  

• Missing Argument

  def greet(name, greeting):
     print(greeting + ', ' + name)
  
  greet('John') # Output: throw error as greeting is not defined
  greet('Jane', 'Hi') # Output: Hi, Jane
  
  

Returns Multiple Value using tuples

def calculate_stats(numbers):
    mean = sum(numbers) / len(numbers)
    variance = sum((x - mean) ** 2 for x in numbers) / len(numbers)
    return mean, variance

result = calculate_stats([1, 2, 3, 4, 5])
print(result) # Output 3.0, 2.0

Partial functions in Python

Lambda functions in Python

Multiple Function Arguments in Python