Functions in Python
Learn to create user-defined functions in Python.
What is a function?
A function is a piece of code that runs only when it’s called. We can input data as parameters to a function. We can also get data as output from a function. Our programs extensively use built-in Python functions. Some examples of built-in functions include range(), len(), round(), and print().
We can also define custom functions known as user-defined functions. In this lesson, we discuss how to create and use user-defined functions.
User-defined functions
The syntax for creating a user-defined Python function is given below.
def function_name(parameters):statement(s)return expression
Python uses the keyword def to define a function followed by the function name. The parameters are input to the function. When we pass real values to a function, they’re called function arguments. A function:
Might not have any parameter as an input.
Runs one or more
statement(s)and returns the output data as anexpression.Might not have a
returnstatement.Might return single or multiple outputs separated by commas. ...