This document contains a presentation on self-learning modules in Python. It discusses: 1. Assigning modules to different students for learning. 2. Modules, packages, and libraries as different ways to reuse code in Python. A module is a file with the .py extension, a package is a folder containing modules, and a library is a collection of packages. 3. The Python standard library contains built-in functions and modules that are part of the Python installation. Common modules discussed include math, random, and urllib.

1. CHAPTER 4
SELF LEARNING
PRESENTATION.
.pptx Format
All images used in this presentation
are from the public domain

4. Friends,
Module 1 assigning to Aswin
Module 3 and 5 goes to Naveen
Module 4 to Abhishek, 2 to Sneha
and .., Abhijith will lead you.

5. I need this
code again
in another
program.

6. Modules, packages, and libraries are
all different ways to reuse a code.
Modules
Packages
libraries

7. A module is a file containing Python definitions and statements. The file name is the module name with the suffix .py appended.
A module is a file containing Python definitions and statements. The file name is the module name with the suffix .py appended.
A module is a file containing Python definitions and statements. The file name is the module name with the suffix .py appended.
Look at the board. There are
some functions, classes, constant
and some other statements.
Absolutely this is a module.
Module is a collection
of functions, classes,
constants and other
statements.

8. Write the code on the board
in a file and save it with a
name with .py suffix.
It becomes a module.

9. Yes2. I want to write
some more module
files.
Can you try your
own modules ?
Good. That is Package.

10. A group of modules saved in a
folder is called package.
I want a package contains
my own modules.
Collection of modules
saved in a folder, are
called package.

11. Library is a collection of packages.
Suppose we write more packages about
anything. It will become a library. In
general, the terms package and library
have the same meaning.

12. PYTHON has rich libraries.
,
.

13. The Python Standard Library contains
built-in data, functions, and many modules.
All are part of the Python installation.
Basic Contents of Standard Library.

14. Built-in
Data,
functions
+ more
Module to import
1. Math module
2. Cmath module
3. Random module
4. Statistics module
5. Urllib module
and

15. print ( "10 + 20 = ", 10 + 20 )
print ( "Cube of 2 is ", 2 ** 3 )
import math
print ("Square root of 25 is ", math.sqrt(25) )
print ("Cube of 2 is ", math.pow(2,3) )
print(), input(),
10 + 20 are basic operation.
No need to import anything.
sqrt () and pow () are defined in
Math module. So need to
import math modules.
We use the
Statement to import other
modules into our programs.

16. hex ( Integer Argument )
oct ( Integer Argument )
int ( string / float Argument )
round ( )
Examples of Built-in Function.
Accept an integer in any
system and returns its
octal equivalent as string.
>>> oct ( 10 )
OUTPUT : ‘0o12’
Accept an integer in any system and returns
its Hexadecimal equivalent as string.
>>> hex ( 10 )
OUTPUT : ‘0xa’
The int() function returns
integer value of given value.
The given float number is rounded
to specified number of
decimal places.
>>> int ( 3.14 )
OUTPUT : 3
>>> round ( 3.65,0 )
OUTPUT : 4.0
In oct, 1, 2, 3, 4,
5, 6, 7, What
next ?

17. oct(),hex() and bin() Functions.
Don't worry. you just count 1 to 20 using
for a in range(1,21) And use hex() and oct()
functions. The computer will do everything for you.
Octal system has only 8
digits. They are 0 to 7. after 7,
write 10 for 8, 11 for 9, 12 for
10 etc.
Hexadecimal system has 16
digits. They are 0 to 9 and 'a'
for 10, 'b' for 11... 'f' for 15.
After 15, write 10 for 16, 11 for

18. print ("Numbering System Table")
print("column 1: Decimal System, col2 : Octal, col3: Hex, col4: Binary")
for a in range(1,25):
print(a, oct(a), hex(a), bin(a) )
Numbering System Table
column 1 :Decimal System, col2 : Octal,
col3: Hex, col4: Binary
1 0o1 0x1 0b1
2 0o2 0x2 0b10
3 0o3 0x3 0b11
4 0o4 0x4 0b100
5 0o5 0x5 0b101
6 0o6 0x6 0b110
16 0o20 0x10 0b10000
17 0o21 0x11 0b10001
18 0o22 0x12 0b10010
19 0o23 0x13 0b10011
20 0o24 0x14 0b10100
21 0o25 0x15 0b10101
22 0o26 0x16 0b10110
23 0o27 0x17 0b10111
24 0o30 0x18 0b11000
oct() convert given value to octal system.
hex() convert given value to Hexadecimal system.
bin() convert given value to Binary system.
OUTPUT
CODE

19. int ( float/string Argument )
round (float , No of Decimals)
int () and round () Function.
The int() function returns integer value
(No decimal places) of given value. The given
value may be an integer, float or a string like “123”
The given float number is rounded to specified
number of decimal places. If the ignoring number is
above .5 ( >=.5) then the digit before it will be added by 1.
>>> int ( 3.14 )
OUTPUT : 3
>>> int (10/3)
OUTPUT : 3
>>> int( “123” )
OUTPUT : 123
>>> round ( 3.65 , 0 )
OUTPUT : 4.0

20. Join the words “lion”, “tiger” and
“leopard” together.
Replace all "a" in “Mavelikkara” with "A".
Split the line 'India is my motherland'
into separate words.
“anil” + “kumar” = “anil kumar”,
“anil” * 3 = “anilanilanil”. These are
the basic operations of a string.

21. string.split() function splits a string into a list.
>>> x = "All knowledge is within us.“
>>>
We get the list ['All', 'knowledge', 'is', 'within', 'us.']
Wrong use Right use
Prefix

22. >>> x = "Mathew,Krishna,David,Ram"
>>> x.split( “,” )
We get the list ['Mathew', 'Krishna', 'David', 'Ram']
Cut when
you see “n“.
>>> x = "MathewnKrishnanDavidnRam"
>>> x.split( “n” )
We get the list ['Mathew', 'Krishna', 'David', 'Ram']
>>> x = "MAVELIKARA"
>>> x.split("A")
We get the list ['M', 'VELIK', 'R', '']
"MAVELIKARA" Is it
Fun
?

23. string.join() joins a set of string into a single string.
Delimit string.join ( collection of string )
“,”. join ( [‘Item1’, ‘Item2’, ‘Item3’] )
‘Item1’
‘Item1,Item2’
1
2
3
Item1,Item2,Item3
End
>>> a = ['Matthew', 'Krishna', 'David','Ram']
>>> ",".join(a) OUTPUT : 'Matthew,Krishna,David,Ram'

24. Do it in Python.
>>> a = ['Trissur','Ernakulam','Kottayam', 'Mavelikara' ]
>>>> "->".join(a)
'Trissur->Ernakulam->Kottayam->Mavelikara'

25. Can you change
zebra to cobra?
replace () Function. replace () Function.
function replaces a phrase with
another phrase.
string.replace(what, with, count )
What to replace?
Replace with what?
How many
replacement is
needed.(optional)
>>> ‘zebra’.replace(‘ze’,’co’)
cobra zebra becomes cobra
>>> ‘cobra’.replace(‘co’,’ze’)
zebra cobra becomes zebra

26. Modules such as math, cmath, random, statistics, urllib are
not an integral part of Python Interpreter. But they are
part of the Python installation. If we need them,
import them into our program and use them.
We use "Import” statement to import
Other modules into our programs.
It has many forms. We will learn in detail later.
Syntax is import < module Name >
E.g. import math
import random

27. Python does a series of actions when you import module,
They are
The code of importing modules is interpreted
and executed.
Defined functions and variables in the
module are now available.
A new namespace is setup for importing modules.

28. A namespace is a dictionary that contains the names and definitions
of defined functions and variables. Names are like keys and
definitions are values. It will avoid ambiguity between 2 names.
I teach 2 Abhijit. one is in class XI-B and
other is in class XII-A. How can I write
theirname without ambiguity.
class XI-B.Abhijit class XII-A.Abhijit

29. Are not Ashwin in 12.B?
Your Reg. No 675323.
No Sir, Check
the list of 12.A

30. Who is കുഴിക്കാലായിൽ
അബ്രഹാാം(K M Abraham)
He is a member of
കുഴിക്കാലായിൽ
family.
An object (variable, functions
etc.) defined in a namespace is
associated with that
namespace. This way, the same
identifier can be defined in
multiple namespaces.
>>> math.
Output : 5
>>> math.pi
Output :3.141592653589793
Google K.M. Abraham.
Name of
Namespace
Object in that
Namespace

31. math
math and cmath modules covers many mathematical
functions.
and .
More than 45 functions and 5 constants are defined in it.
The use of these functions can be understood by their
name itself.
2. Place (Namespace) before function name.
1. import math
X = sqrt(25)
Name of
Namespace
Object in that
Namespace

32. >>> locals()
{'__name__': '__main__', '__doc__': None, '__package__': None,
'__loader__': <class '_frozen_importlib.BuiltinImporter'>,
'__spec__': None, '__annotations__': {}, '__builtins__': <module
'builtins' (built-in)>}
>>> import math
>>> locals()
{'__name__': '__main__', '__doc__': None, '__package__': None,
'__loader__': <class '_frozen_importlib.BuiltinImporter'>,
'__spec__': None, '__annotations__': {}, '__builtins__': <module
'builtins' (built-in)>, 'math': <module 'math' (built-in)>}
>>>

33. >>> help(math)
Traceback (most recent call last): File "<pyshell#1>", line 1, in <module>
help(math)
NameError: name 'math' is not defined
>>> import math
>>> help (math)
Help on built-in module math:
NAME
math
DESCRIPTION
This module provides access to the mathematical functions
defined by the C standard.

34. FUNCTIONS.
import math
The value without –ve / +ve symbol is called
absolute value. Both functions give absolute value, while fabs () always give a float
value, but abs () gives either float or int depending on the argument.
>>> abs(-5.5) >>> abs(5)
Output : 5.5 5
>>> math.fabs(5) >>> math.fabs(5.5)
Output : 5.0 5.5
Returns factorial value
of given Integer. Error will occur if you enter a -ve or a float value.
>>> >>> math.factorial(-5)
Output : 120 >>> math.factorial(5.5)
Wrong use
Right use
Abs() is built-
in function.

35. Interesting, right?
This is just a sneak preview of the full presentation. We hope
you like it! To see the rest of it, just click here to view it in full
on PowerShow.com. Then, if you’d like, you can also log in to
PowerShow.com to download the entire presentation for free.