How to Define and Use Python Functions

In this example we will show how to use functions in Python.

2. Definition of Functions

The function code block begins with the def keyword, followed by the function identifier name and parameters.
Arguments need to be placed between the parentheses ().
Return [expression] returns a value to the caller. Return without expression is equivalent to returning None.

Syntax of the function：

def function_name( parameters ):

   function_suite
   return [expression]

Source Code

Example 1 (No parameter):

#define function
def getName():
    Str=input('please input your name:')
    print('your name is ', Str)

# invoke the function
getName()

Output:

please input your name: John
your name is John

Example 2 (multiple parameters):

#define function
def getSum(a, b):
    tmp = a + b;
    return tmp

x = int(input('Please input the first value: '))
y = int(input('Please input the second value: '))

# invoke this function
print('The sum of %d and %d is %d '%(x, y, getSum(x, y)))

Output:

Please input first value: 3
Please input second value: 2
The sum of 3 and 2 is 5