Functions In Python

Lecture 60:-  Functions In Python

In Python, a function is a reusable block of code that performs a specific task or set of tasks. Functions allow you to break down a complex problem into smaller, manageable tasks, making your code more organized, modular, and easier to maintain. Functions help promote code reusability and improve readability.

A function in Python is defined using the def keyword, followed by the function name, parentheses (), and a colon :. The body of the function is indented and contains the code that will be executed when the function is called. Here's the basic syntax of a function:

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def function_name(parameters):    # Function body (code)    # ...    # Optional return statement    # ...

Here's an explanation of the components of a function:

• def: The keyword used to define a function.
• function_name: The name of the function, following the Python identifier rules.
• parameters: Optional input parameters that the function can accept. Multiple parameters are separated by commas. These parameters act as placeholders for values that can be passed to the function when it is called.
• Function body: The block of code that defines what the function does. This code is indented under the def statement and is executed whenever the function is called.
• return: An optional statement that specifies the value or values that the function will return to the caller. If the function does not have a return statement, it implicitly returns None.

Here's an example of a simple function that adds two numbers:

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def add_numbers(a, b):    sum_result = a + b    return sum_result # Example usage: result = add_numbers(10, 20) print("Sum:", result)

Output:

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Sum: 30

In this example, we defined a function called add_numbers that takes two parameters a and b. The function adds these two parameters together and returns the result using the return statement. When we call the function with add_numbers(10, 20), it returns the sum of 10 and 20, which is 30, and we print the result.

Functions can be more complex and can contain conditional statements, loops, and other functions within them. They are an essential concept in Python programming for code organization and reusability.