Python functions:

Function: are pre-written lines of code that do a specific task.

Function: are composed of:

1. Definition code line.

2. Argument.

3. Retrun or print or yield or result making lines of code.

Python functions:

We define our own functions in Python and reuse them in the same program as many times as we need.

def function_name(parameters):

lines of code of the function should do

return something

Variable Scope:

There two types of variables according to variable scope:

Local variable:

When the variable located and assigned to data value inside the function only, so it will affect that data value of the that variable inside that function only.

Global variable:

When the variable located and assigned to data value outside the function, so it will affect that data value of the that variable inside and out side that function.

Python functions examples:

1.Function That returns a value according to its argument :

>>>def rectangle_area(width, length)

area = width * length

return area

>>>def rectangle_area(6, 9)

Result :54

>>>def rectangle_area(4, l5)

Result : 20

2. Function that returns Boolean value :

Example 1:

def is_even(x):
if x % 2 == 0:
return True
else:
return False
>>>def is_even(10)

Result: True

2. Function that returns Boolean value:

Example 2:

def is_odd(y):
if y % 2 == 0:
return True
else:
return False
>>>def is_odd(8)

Result: False

3.Function that prints specific data:

Example 1:

def countdown(x):
while x> 0:
print n
x = x-1
print “Stop this is the end!"
>>>def countdown(2)

Result: 2

1

Stop this is the end!

3. Function that print specific data:

Example 2:

def is_even_or_odd(n):
if n % 2 == 0:
return “this number is even”
else:
return “this number is odd”
>>>def is_even_or_odd(2)

Result: this number is even

>>>def is_even_or_odd(7)

Result: this number is odd