This document discusses creating modules in Python. It explains that modules allow for better organization of code by defining classes, functions, and variables that can be imported and used in other files. It provides an example of creating a calculator module with add and sub functions, and shows how that module can be imported and its functions called from another file to perform calculations. It also demonstrates importing specific functions from a module using the from keyword.

1. Python for Ethical Hackers
Mohammad reza Kamalifard

2. Python Language Essentials
Part 6 :
Creating Modules

3. Modules
Better way to orgnizing code
can define classes,functions and variables
Import a module:
import MODULE_NAME
form MODULE_NAME import ….

4. Creating Module
$ vim calculator.py
#!/usr/bin/env python
'''
This is a simple calculator
add for addition
sub for subtraction
'''
def add(a, b):
return a+b
def sub(a, b):
return a-b
~
~

5. Creating Module
$ vim calculator.py
#!/usr/bin/env python
import calculator
print '2 + 3 is equal to : %d ' % calculator.add(2,3)
print '10 - 3 is equal to : %d ' % calculator.sub(10,3)
~
~
$ chmod a+x testcalc.py
$ ./testcalc.py
2 + 3 is equal to : 5
10 - 3 is equal to : 7

6. from … import
$ vim testcalc.py
#!/usr/bin/env python
from calculator import add
print '2 + 3 is equal to : %d ' % calculator.add(2,3)
print '10 - 3 is equal to : %d ' % calculator.sub(10,3)
~
$ ./testcalc.py
2 + 3 is equal to : 5
Traceback (most recent call last):
File "./testcalc.py", line 6, in <module>
print '10 - 3 is equal to : %d ' % sub(10,3)
NameError: name 'sub' is not defined

7. This work is licensed under the Creative Commons
Attribution-NoDerivs 3.0 Unported License.
To view a copy of this license, visit
http://creativecommons.org/licenses/by-nd/3.0/
Copyright 2013 Mohammad reza Kamalifard.
All rights reserved.