Functions in Python for Beginners

Functions are a central concept in Python programming. They allow you to create reusable code that significantly enhances the readability and maintainability of your program. Below, you will learn how to create, call, and effectively use functions in Python. You can expect practical examples and a step-by-step guide to help you develop a deeper understanding of working with functions.

Key insights

Functions are a practical means to structure and reuse code. Their basic structure consists of the keyword def, followed by a name and a parameter list. Once defined, a function can be called anytime and anywhere in the code. This saves time and effort when you need the same block of code multiple times.

Step-by-step guide

1. The structure of a function

First, take a look at the basic syntax of a function. Start with the keyword def, followed by a function name and a parameter list in parentheses. A colon concludes this, and immediately after it, you follow with the statements that the function should execute.

2. Creating a simple function

To demonstrate how a simple function works, you will now create a function that simply outputs "Hello". Name this function say_hello.

This function contains only one statement after the colon. It outputs the text "Hello" when you call it.

3. Calling a function

To execute this function, you simply call it in your program. This is done by using the function name followed by parentheses. For example:

say_hello()

The result should display "Hello" in your terminal. You can repeat this call multiple times to see that the function outputs the same text each time.

4. Defining a function with variables

Now let's expand the function. Suppose you want a function that outputs two values.

Here, two variables are defined and outputted when the function is called.

5. Calling the function

To execute the updated function, you again use the call show_numbers() in your code.

Once the function is defined, it does not matter where in the code the call is made – you can place it anywhere.

6. Functions with parameters

In the next step, it gets exciting: You will learn how to create functions with parameters.

Here, the function accepts two values that it adds together and outputs the result.

7. Calling a function with parameters

The result is the sum of the two values, which in this case is "15". You can pass different values to get different results.

8. The next step with return values

So far, we have used only functions without return values. To gain more flexibility, you can also define a return value.

Here, the function returns the product of the two parameters.

9. Working with the return value

You process the return value, which gives you more options in programming.

10. Summary and outlook

Functions are a fundamental concept in Python that helps you organize and reuse your code. You have learned how to define and call functions, both simple outputs and those with parameters and return values. You are well-prepared to further explore functions, including more complex applications and working with parameters in the next video.

Summary – Python functions for beginners

In this tutorial, you have learned the basics of function definition in Python. You have created simple functions, called them, used variables, and experimented with return values. Functions are a valuable tool that will help you write more efficient and maintainable programs.