Programing and Problem Solving
Mr. P.S. Desai
Course Objective
Prime objective is to give students a basic introduction to
programming and problem solving with computer language
Python. And to introduce students not merely to the coding of
computer programs, but to computational thinking, the
methodology of computer programming, and the principles of
good program design including modularity and encapsulation.
Course Objective
1.To understand problem solving, problem solving aspects,
programming and to know about various program design tools.
2.To learn problem solving with computers
3.To learn basics, features and future of Python programming.
4.To acquaint with data types, input output statements, decision
making, looping and functions in Python
5.To learn features of Object Oriented Programming using Python
6.To acquaint with the use and benefits of files handling in Python
Course Outcomes:
On completion of the course, learner will be able to–
Co1: inculcate and apply various skills in problem solving.
CO2: Choose most appropriate programming constructs and
features to solve the problems in diversified domains.
CO3: Exhibit the programming skills for the problems those require
the writing of well documented programs including use of the logical
constructs of language, Python.
CO4: Demonstrate significant experience with the Python program
development environment
Unit I Problem Solving , Programming and Python
Programming
Part A: General Problem Solving Concepts :
1.
2.
3.
4.
5.
6.
7.
Problem Solving in everyday life
Types of Problem
Problem solving with computer
Difficulties with problem solving
Problem Solving Aspects
Top - Down Design
Problem Solving Strategies
Unit I Problem Solving , Programming and Python
Programming
Part B: Program Design tools
1.
2.
3.
4.
Algorithm
Flowchart
Pseudo -codes
Implementation of Algorithm
Unit I Problem Solving , Programming and Python
Programming
Part C: Python Programming :
1.
2.
3.
4.
5.
6.
7.
8.
Features of Python
History and Future of Python
Writing and executing Python program
Literal constant , Variable and identifiers
Data types
Comments , Reserved words , Indentation
Operator and Expression
Input Operation
General Problem Solving Concepts : Problem Solving in everyday life
What is Problem ?
1.
2.
A Problem is a state of difficulty that need to be resolved
While solving a problem there is a desire to attain some specific
goal .
Here is some examples we face in day to day life can be important or
can be least importance .
1.
2.
3.
4.
Will I get proper transport to go to my workspace ?
Should I wear shoes today ?
Should I go to a movies ?
Which Mobile phone should I buy?
General Problem Solving Concepts : Six steps of Problem Solving
1. Define the Problem
2. Determine the Root Cause(s) of the Problem
3. Develop Alternative Solutions
4. Select a Solution
5. Implement the Solution
6. Evaluate the Outcome
Six steps of Problem Solving
Step -1
Step-2
Step-3
Step-4
Step-5
Step-6
Types of Problem
1.
Problem Based on algorithmic solution :
Sequence of instruction .
For solving some problem , series of actions are taken to reach the solution.
2.
Problem
based on heuristic Solutions :
The Solution that can not reached through direct set of steps are called heuristic
solutions .
With heuristic solution problem solver has to follow six steps of problem solving for more
than once .
Problem solving with computer
Solution : In is the instruction that must be followed to produce the beat
result .
Results: It is an outcome or the completed computer -assisted answer .
Program : Computer program are set of instructions executed to obtain
solution to certain problem . These programs are written in some
specific programming language.
Computer deal with the problem having algorithmic solution .
The field of computer that deal with solving the heuristic problems is
called artificial intelligence .
Difficulties with problem solving
1.
2.
3.
4.
5.
We do not understand the problem correctly .
Sometimes we do not define the problem correctly or adequately
People get afraid of taking decisions while solving the problems
Sometimes thee list of alternatives is incomplete .
The sequence of solutions to the problems is not logical many
times .
6. When solving problem on the computer , one of the most difficult
tasks for the problem solver is writing the instructions .
Problem Solving Aspects
Mainly focus on
1.
2.
3.
4.
5.
6.
Problem Definition phase
Problem Solving Phase
Use of specific Example
Similarities among problems
Working backwards from the solution
General Problem solving strategies
Top - Down Design
Top- Down approach is essentially the breaking down of a
system to gain insight into the subsystem that make it up.
An overview of the system is formulated . Each subsystem is
then refined in yet greater detail, sometimes in many additional
subsystem levels , until the entire specification is reduced top
base elements .
The top design strategy is also known as stepwise refinement .
Top - Down Design
Problem Solving Strategies
1.
2.
3.
4.
5.
Requirement Analysis
Desgin
Implementation
Testing
Software Deployment , training and Support
Part B: Program Design tools:Algorithm
1.
2.
3.
4.
5.
6.
Algorithm gives the logic of the program , that is , a step- by -step description
of how to arrive at a solution .
An Algorithm provides a blueprint to writing a program to solve a particular
problem .
It is considered to be an effective procedure for solving a problem in a finite
number of steps .
That is , a well defined algorithm always provides an answer , and is
guaranteed to terminate .
Algorithms are mainly used to achieve software reuse .
Ones we have an idea or a blueprint of a solution , we can implement it in any
language such as C ,C++, Python, JAVA and so on.
Different Approaches to Designing an Algorithm
Algorithm are used to manipulate the data for given problem .
For a complex problem, its algorithm is often divided into smaller units called
modules .
This process of dividing an algorithm into modules is called modularization .
There are Two approaches to design an algorithm
1.
2.
Top-Down Approach
Bottom- up approach
Control structure used in Algorithm
An algorithm has a finite number of steps and some steps may involve decision
making and repetition .
Broadly speaking an algorithm may employ three control structures, namely
Sequence , Decision , Repetition.
Sequence : Sequence means that each step of algorithm is executed in the
specific order.
Decision : Decision statement are used when the outcome of the process
depends on some condition .
Repetition : Which involves executing one or more steps for a number of times
.
Examples of Algorithm
1. Write an algorithm for swapping two number
2. Write an algorithm to find the larger of two number
3. Write a algorithm that number is even or odd
Flowchart
A flowchart is a graphical or symbolic representation of a process .
Flowchart is pictorial view of algorithm
When designing a flowchart , each step in the process is depicted by
different symbol and is associate with short symbol .
Flowchart Symbol
Examples of Flowchart
1.
2.
3.
4.
Draw a flowchart to calculate the sum of first 10 natural number
Draw a flowchart to add two number
Draw a flowchart to calculate the salary of a daily wager
Draw a flowchart to determine the largest of three numbers
Pseudocodes
Pseudocodes is a compact and informal high level description of an
algorithm that uses the structural conventional of a programming
languages.
Pseudocode must be complete , describing the entire logic of the
algorithm , so that can be translated strainghway into a programming
languages.
Pseudocode are an outline of a program that can easily be converted into
programing statements .
Pseudo Codes examples
1. Write a psudocode for calculating the price of product after adding the
sales tax to its original price .
Part C: Basics of Python Programming
Python has been
consecutively topping the
most loved programming
language on the
StackOverflow developers
survey report. (Ref.
https://data-flair.training/blo
gs/python-career-opportunit
ies/)
Growth of Python
Importance of Python
●Python is used in Data Science
●Python used with Big Data
●Python used in Artificial Intelligent
●Python used in Scripting and automation
Job Profile in Python
Python Web Developer
Software Engineer
Data Analyst
Data Scientist
Machine Learning Engineers
DevOps Engineer
Research Analyst
Product Manager
Features of Python
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Simple
Easy to learn
Free and open source
High level language
Intrative
Portable
Object oriented
Embeddable
Secure
Dynamic
History of Python : Inventor
Guido Van
Rossum
Interview: Guido van Rossum:
The Early Years of Python
Coursera Interview Link of
Guido Van Rossum : Click
Interview Reference :
https://www.coursera.org/
Why is it called ‘Python’?
Monty Python’s
Flying circus ( a
BBC Comedy
series from the
70’s)
Version details
1.
2.
3.
4.
5.
Version 1.0 was released in 1991.
Version 2.0 was released in 2000 .
Python 2.7 last release of 2.0 version.
Python 3.0 was relased in 2008.
Current version is 3.6.4.
Interview: Guido van Rossum - The Modern
Era of Python
Coursera Interview Link of Guido Van
Rossum : Click
Interview Reference :
https://www.coursera.org/
Application of Python
1.
2.
3.
4.
5.
6.
7.
Embedded Scripting Language
GUI-based desktop application
Image processing and Graphic design application
Games
Enterprise and Business application
Operating System
Language Development
Writing and Executing First Python Program
1.
2.
3.
4.
Open an editor
Write the instruction
Save it as a file with the filename having the extension .py
Run the interpreter with the filename having extension .py
Example
print(“Hello all welcome to Python world of Joy”)
Building Blocks of Python Programming Language
1.
2.
3.
4.
5.
6.
7.
8.
Constants
Variables
Identifiers
Data Types
Reserved words
Indentation
Operators
Expressions
Constants
Fix values such as numbers , letters and strings are called constsant because their values does not
change .
print(576)
print(5.6)
print(“Hello World”)
big part of any programming language is the syntax for constants. So, like a 576 or 5.6, numbers both
integer and floating point numbers. We've been using this on calculators. They make a lot of sense to us.
The kind of constants that are a little bit different are things like string constants. So "Hello world" is a
string constant. We use that so that our program can say nice things to people that are using our program.
And so, we call them constants because they don't change but it's kind of obvious, constants.
Variable and Identifiers
Using just constants you cannot do much in your program .For developing
little complex program , you need to store information and manipulate it as
required .THis is where variables can help.
Variables are reserved memory locations that stores values.
Identifiers are names given to something .
This somethings can be a variable , function, class , modules or objects.
Choice variable name sensible.
Python Variable Name Rules
Must start with letter or (_) underscore .
Must consist of letter , number and _ underscore .
Punctuation characters such as @ , $ , % not allowed within names.
Case sensitive
Good: sum, _My_var , num1 , r, var_20
Bad: 1num , %check , Basic sal , H#R&A
Difference : check , Check , CHECK
Data Types
Variables can hold values of different types called data types .
We need different data types to store different types of values in the
variables .
Based on the data type of a variable, the interpreter reserves the
memory for it and also determines the data that can be stored in the
reserved memory .
Data types supported by Python
1.
2.
3.
4.
5.
Numbers
String
List
Tuple
Dictionary
Data types with example
Num-7
# number: integer
amt=7.5
#number : Floating
code=’a’
#String
pi=3.1415926536
msg=”Hi”
# number : Floating
# String
Reserved Words
You cannot use reserved words as variable names/identifiers .
Certain words which have a predefined meaning.
Indentation
Whitespace at the beginning of the line called indentation
Example
Age =7
price=10
count=6
Indentation
These whitespaces are very important in python
In most programming languages , indentation has no effect on
program logic.
In python indentation has a major effect on program logic.
In python , indentation is used to associate and group statements .
Operators and Expression
x=2
x=x+2
print(x)
Operators and Expression
x1q3z9ocd=35.0
x1q3z9afd=12.50
x1q3p9afd=x1q3z9ocd*x1q3z9afd
a=35.0
b=12.50
c=a*b
print(c)
hours=35.0
rate=12.50
pay=hours*rate
print(pay)
Variable name and expression
Types of Operator
1.
2.
3.
4.
5.
6.
7.
Arithmetic operators
Assignment operators
Comparison operators
Logical operators
Membership operators
Identity operators
Bitwise operators
Arithmetic operators
Assignment operators
Comparison operators
Logical operators
Identity operators
Membership operators
Bitwise operators
Operator Precedence and Associativity
Program Examples