Python functions are reusable blocks of code that perform specific tasks. Here's how to define them:

Basic Syntax 💡

def function_name(parameters):
    # code block
    return value
python_function_definition

Parameters & Arguments 📌

  • Parameters are variables listed in the function definition
  • Arguments are the actual values passed when calling the function
  • Default values can be set: def greet(name="World"):

Return Values 🚀

Use return to output results from a function.
Example: 

def add(a, b):
    return a + b
function_return_value

Example Code 📜

def calculate_area(radius):
    π = 3.14159
    return π * radius**2

# Calling the function
area = calculate_area(5)
print(area)  # Output: 78.5395

Best Practices ✅

  1. Use descriptive names
  2. Keep functions focused on single tasks
  3. Include docstrings for documentation
  4. Handle edge cases with error checking

For more advanced topics like lambda functions or decorators, check out /en/Python/Functions/Advanced.