Previous lesson: Cycle for A function is a block of code that only runs when it is called. You can pass data known as parameters to a function. As a result, the function has the ability to return data.
Table of Contents
Creating a Function
A function in Python is defined with the keyword def:
def my_function():
print("Hello from function")
Function Call
To call a function, use the function name followed by parentheses.
def my_function():
print("Hi from function")
my_function()
Conclusion:
Hello from the function
Parameters
Information can be passed to a function as a parameter. Parameters are listed after the function name, inside the brackets. You can add as many parameters as you want by separating them with a comma. The following example is a function with one parameter(fname). When the function is called, we pass the name, which is used inside the function to print the full name:
def my_function(fname):
print(fname + "Popov")
my_function("Andrei")
my_function("Vlad")
my_function("Nikita")
Output:
Andrey Popov
Vlad Popov
Nikita Popov
The default value of the parameter
In the following example you can see how to use the default parameter value. If we call a function without a parameter, it uses the default value:
def my_function(country="England"):
print("I'm from " + country)
my_function("Poland")
my_function("China")
my_function()
my_function("USA")
Output:
I am from Poland
I am from China
I am from England
I am from USA
Return value
To return a function value, use the operator return:
def my_function(x):
return 5 * x
print(my_function(3))
print(my_function(5))
print(my_function(9))
Output:
15
25
45
