Want to know how to call a function in Python?

Python is an incredibly versatile and powerful programming language used for many different tasks. One of the key elements of programming with Python is calling functions, which are lines of code that help a program carry out certain tasks.

Functions make code more efficient, organized and reusable. They can be used to build larger programs from smaller pieces of code.

In this In Easy Steps tutorial, you’ll learn all about how to call a function in Python with the help of lots of examples. Let’s dive in!

How to define a function in Python

Functions in Python are defined using the \def\ keyword, followed by the function name, a set of parentheses that may contain parameters and a colon. The code inside the function is indented and the function definition is ended by a return statement.

Here is an example of a function definition in Python:

• In this example, we define a function named \greet\ that takes a single parameter \name\.
• The function then prints a greeting message using the given \name\.
• When the function is called, it will execute the code inside the function definition.

Functions can take zero or more parameters, which are values passed to the function when it is called. These parameters can be used within the function to perform calculations or other operations. Functions can also return values using the return statement, allowing the function to be used as part of expressions or within other functions.

How to call a function (with 2 examples)

Functions in Python can be called by their name, followed by a set of parentheses that may contain arguments. The arguments are values passed to the function when it is called, and are used within the function to perform calculations or other operations.

Here is an example of calling a function in Python:

• In this example, we define a function \add_numbers\ that takes two parameters \a\ and \b\.
• The function then calculates the sum of \a\ and \b\ and returns the result using the \return\ statement.
• To call the function, we use its name \add_numbers\ followed by a set of parentheses containing the arguments we want to pass to the function.
• In this case, we call the function with the arguments \3\ and \5\.
• The result of the function call is assigned to the variable \result\, which we then print to the console.
• This results in the output \8\.

Here’s another example of calling a function in Python, this time with a more complex example:

• In this example, we define a function \process_data\ that takes two parameters \data\ and \operations\.
• The function then performs a set of operations on the \data\ list, depending on the values in the \operations\ list.
• In this case, the function squares each element in the \data\ list if the operation is \”square”\, and sorts the list if the operation is \”sort”\.
• To call the function, we use its name \process_data\ followed by a set of parentheses containing the arguments we want to pass to the function.
• In this case, we call the function with the arguments \numbers\ and \operations\, which are the lists [1, 2, 3, 4] and [“square”, “sort”] respectively.
• The result of the function call is assigned to the variable result, which we then print to the console. This results in the output [1, 4, 9, 16].

Arguments

Arguments in Python are values passed to a function when it is called, used within the function to perform calculations or other operations.

Here’s an example of using arguments in a Python function:

• In this example, the function \add_numbers\ takes two arguments \a\ and \b\ and returns their sum.
• When the function is called, we pass the values \3\ and \5\ as arguments, and the result of the function is assigned to the variable result, which is then printed to the console.
• The output of this code is \8\.

Return Values

To let a function return a value in Python, use the \return\ statement followed by the value to be returned. For example:

• In this example, the function \square\ takes a single argument \x\ and returns its square using the \return\ statement.
• When the function is called, it executes the code within the function definition until it reaches a \return\ statement, at which point it returns the specified value and stops executing the function.
• The value returned by the function can be used in other parts of the program, such as being assigned to a variable or used as part of an expression.

Functions can have multiple return statements, but typically only the first one encountered is executed, as the function terminates as soon as a return statement is executed.

Key takeaways

• Functions are a way to encapsulate a piece of code and reuse it multiple times in a program.
• Functions are defined in Python using the def keyword, followed by the function name, and the function arguments in parentheses. The code within the function is indented and executed when the function is called.
• Functions can take arguments as input, which can be used within the function to perform operations.
• Functions can return a value using the return statement, which stops the execution of the function and returns the specified value to the caller.
• Return values and arguments make functions a powerful tool for breaking down complex tasks into smaller, more manageable pieces, and for creating higher-level abstractions and better organization of code.

More resources

I hope this tutorial helps you learn how to call a function in Python.

If you want to learn more, you can check out our full guide, Python.

We also have lots of other tutorials:

• How do you use “n” in Python?
• How to create ordered lists in a HTML document
• How to add and edit an image in Microsoft Word

Happy coding 🙂