This document discusses Python libraries, including how to import modules, use standard library functions and modules, and create custom Python libraries. It explains that a library is a collection of modules that provide functionality for specific needs. Modules can be imported individually or all at once. The document also gives examples of using mathematical, string, and random functions from the Python standard library. It provides instructions for creating a package by defining a directory structure with packages and modules, and including an __init__.py file.

1. CBSE
CLASS 12
CH-4
USING PYTHON LIBRARIES
SasikalaJayaprakash

2. Topics to be discussed
 What is library
 Importing modules in python program
 Using python standard library’s functions and
modules
 Creating python library

3. What is library
• A library refers to a collection of modules that together cater
to specific type of needs or applications.
• Library have one or more packages and subpackages
• Module is independent grouping of code and data(variables ,
definitions ,statements ,& functions). File extn .py
Syntax : help<module name> # to see docstrings , variables ,
constants , functions

4. Importing module
Two ways
• Entire module
import <module name>
• To import selected object from a module:
from<module name > import <fn name>
To import single object
To import multiple objects
To import all objects
from <module name > import *

5. library’s functions
• Mathematical function
len()
pow()
str()
int()
float()
range()
type()
abs(x)
divmod(a,b)
sum(iterable),sum(iterable,args),
max(iterable),max(iterable , args),
min(iterable),min(iterable,args),
Oct (integer)
hex(integer)
• String functions
<str>.join
<str>.split
<str>.replace

6. Using python standard library modules
• Random module
random() - 0 <=N<1
randint(a , b) a<=N<=b
random.uniform(a , b) floating point a<=N<=b
random.randrange(stop)
random.randrange(start , stop , step) (0,50,10)

7. • String module
string.ascii_letters
string.ascii_lowercase,
string.ascii_uppercase,
string.digits,
string.hexdigits,
string.octdigits ,
string.punctuation ,
capwords(<str>,[sep=none])

8. Creating a python library
• Package – collection of modules
_init_ .py – special file

9. Procedure for creating package

10. Creating package
• Decide about basic structure of package
• Create the directory structure having folders
with names of packages
• Create a __init__.py file in a package

11. Creating package
Geometry
volume
area
Rectangle() cube()
Square() cubiod()
Triangle()
Package
modules
functions

12. Creating Package(Geometry)

14. Importing package geometry , module
area

15. Area python file coding

16. Volume python file coding