Python Modules

Python modules 

Python Modules

Modules in Python :

 1.What is a Module ?

i)Modules are nothing but collections of different functions under a signal unit .
ii)Modules are pre-written pieces of code that are used to perform common tasks like 
    generating numbers,performing basic mathematical operations etc.

            Till now we had learnt about functions in python which help us to reuse a particular 
piece of code ,Modules goes a step ahead . " It allows you to reuse one or more functions
in your programs , even in that program that functions have not been defined " the 
program in which user want to use functions defined in a module will simply import that 
particular module. 

2.HOW TO IMPORT A MODULE ?

-SYNTAX = import module name      OR       from module-name import *  

          A module import in a program must be loaded into a memory before it can be used .
Python First search for that module in current working directory .If  the module is not found
there ,then it looks for the modules in the directories specified in python-path environment 
If module still not found there ,then python (Compiler) search that module in 
PYTHON-INSTALLATION_SPECIFIC-PATH, If the module in not located even there then
compiler passes an error.

The From import statement 
A module may contain definition for many variables or functions define in that module 
But when a user wants to use only a particular function then this statement is used. when more then one function is required then comma is placed in between there names.

  NOTE
from math import * statement imports all names except those beginning
with an underscore (_).


EXAMPLE :

 from math import e
 print("Value of e=",e)

OUTPUT :
Value of e = 2.718281828459045



3.WHAT IS USED OF " AS ” KEYWORD ?

- User can import a module with a different name using " as " keyword .this is particularly 
particularly when a module name is long or confusing .

EXAMPLE : 

from math import sqrt as square_root
print(" Square root of 49 =", square_root(49))

OUTPUT:

Square root of 49 =  7.0

4.How to find the name of a particular module ?

-Every module has a name .user can find name of module by using Syntax(__name__)

EXAMPLE:

from math import sqrt as square_root
print(" Square root of 49 = ",square_root(49))
print(__name__)

OUTPUT:
Square root of 49 =  7.0
__main__

STANDARD LIBRARY MODULES 
Python supports three types of modules those written By the programmer ,those that are 
pre-installed from external sources, and those that are pre-installed with python.Modules
that are pre-installed in python are called as STANDARD LIBRARY FUNCTION .

PYTHON MODULES LIST


1.string                            11.doctest
2.datetime                     12.unittest
3.re                                    13.pdb
4.time                               14.argparse  
5.math                             15.sys
6.random                        16.array
7.os
8.multiprocessing
9.subprocess 
10.socket

   User can use these modules for performing tasks like string parsing,data serialization ,testing,
dubbing and manipulating dates ,emails ,command line arguments etc.

I hope this article on modules is helpful for You ,in next one we will discuss about creating
 Our own modules,and packages in python.


                                                           Thank u 😊