Python

1. BY
DR.BELMER GLADSON.V M.E.,Ph.D.,
ASSOCIATE PROFESSOR
ADHI COLLEGE OF ENGINEERING AND TECHNOLOGY

2. CONTENTS
 INTRODUCTION
 PROBLEM SOLVING TECHNIQUES
 ALGORITHMIC STRATEGIES
 FUNCTIONS
 PYTHON – VARIABLES AND OPERATORS
 CONTROL STRUCTURES
 STRINGS AND STRING MANIPULATION
 LIST,TUPLES AND DICTIONARY

3. INTRODUCTION
 Python is a general-purpose interpreted, interactive,
object-oriented, and high-level programming
language.
 It was created by Guido van Rossum during 1985- 1990

4. Why to Learn Python?
 Python is a high-level, interpreted, interactive and
object-oriented scripting language.
 Designed- highly readable.
 Uses English Keywords frequently.
 To become a great Software Engineer – Web
Development Domain.
 Python is Interpreted
 Python is Interactive
 Python is Object-Oriented
 Python is a Beginner's Language

5. Applications of Python
 Easy-to-learn
 Easy-to-read
 Easy-to-maintain
 Interactive Mode
 Portable
 OpenSource
 Real Time Applications
 Bit Torrent file sharing
 Google search engine, YouTube
 Face book, Drop box

6. PROBLEM SOLVING TECHNIQUES
 Define the problem and creating number of solutions.
 Starts –Problem specification, Ends – Correct
Program.
PROBLEM SOLVING TECHNIQUES
• Set of techniques that helps in providing logic –solve
the problem.
1. Algorithms.
2. Flowcharts.
3. Pseudo codes.
4. Programs

7. ALGORITHM
 Sequence of instructions that describe a method.
Qualities of an Algorithm:
 Should be written in simple English
 Should be precise and unambiguous.
 Should not be repeated infinitely.
 should conclude after a finite number of steps.
 Should have an end point
 Derived results should be obtained only after the
algorithm terminates.

8. Example:
Addition of Two Numbers:
1.Start
2. Read the value of ‘a’
3. Read the value of ‘b’
4. Calculate sum=a+b
5. Print the sum of two number
6. Stop

9. Flowchart
---Graphical Representation of an Algorithm

10. Example:

11. Pseudocode
 Informal high-level description.
 Example:
 To find sum of two numbers
1.READ num1,num2
2.sum=num1+num2
3.PRINT sum

12. Program
 Program= Algorithm +Data
 Set of instruction, to the computer to solve a problem.
 Accept the data to perform computation.

13. ALGORITHMIC STRATEGIES

14. FUNCTIONS
 Block of organized, reusable code that is used to
perform a single, related action.
 Methods, sub-routines.
 Syntax
function_name(parameters)
function statements
end function

15. Algorithm for addition of two
numbers using function
 Main function()
Step 1: Start
Step 2:Call the function add()
Step 3: Stop
• Sub function add()
Step1:Functionstart
Step2:Geta,bValues
Step 3: add c=a+b
Step 4: Print c
Step 5: Return

16. VARIABLES:
 Store a value by assigning it to a name.
 It can be of any length. No space is allowed
 Assigning value to variable:
 >>>counter =45
print (counter)
 single value to several variables
a=b=c=100
 Multiple values to multiple variables
>>>a,b,c=2,4,"ram"

17. OPERATORS
 Constructs which can manipulate the value of operands.
expression 4 + 5 = 9
 Types of Operators
 Arithmetic Operators
 Comparison (Relational)Operators
 Assignment Operators
 Logical Operators
 Bitwise Operators
 Membership Operators
 Identity Operators

18. Arithmetic operators:

19. Comparison (Relational)Operators

20. Assignment Operators

21. Logical Operators:

22. Bitwise Operators:

23. Membership Operators:

24. CONTROL STRUCTURES
 Conditional Statements
Conditional if
Alternative if… else
Chained if…elif…else
Nested if….else

25. Conditional if

26. Alternative if… else

27. Chained if…elif…else

28. Example

29. Nested if….else

30. Example:

31. STRINGS AND STRING MANIPULATION
 Series or sequence of characters
 Strings are marked by quotes:
Single quotes(' ') E.g., 'This a string in single quotes'
Double quotes(" ") E.g., "'This a string in double quotes‘”
Triple quotes(""" """)E.g., """This is a paragraph. It is
made up of multiple lines and sentences.""“
 Strings are Immutable

32. Operations on string

33. Lists
 List is an ordered sequence of items
 square brackets[]
 Items in the lists can be of different datatypes
 Operations on list: Indexing, Slicing ,Concatenation
Repetitions, Updation, Insertion, Deletion

34. Operations on list

35. Tuple:
 A tuple is same as list
 Parentheses()
 A tuple is an immutable list
 Benefit of Tuple:
 Tuples are faster than lists.
 If the user wants to protect the data from accidental changes,
tuple can be used

36. Basic Operations:

37. Dictionaries
 Dictionaries are unorderedsets.
 curly brackets{}
 Dictionaries are accessed via keys

38. Operations: