It covers the various basics and fundamentals aspect of Python Programing

Python Overview
Python is a high-level, interpreted, interactive and
object oriented-scripting language.
Python was designed to be highly readable which uses
English keywords frequently where as other languages
use punctuation and it has fewer syntactical
constructions than other languages.
COPYRIGHT © DR.GARGISHANKAR VERMA , PROFESSOR KRISHNA VIKASH INSTITUTE OF TECHNOLOGY, RAIPUR

1.Step 1: Check Your System. ...
2.Step 2: Download Python. ...
3.Step 3: Choose the Right Version. ...
4.Step 4: Download the Installer. ...
5.Step 5: Run the Installer. ...
6.Step 6: Verify the Installation. ...
7.Step 7: Install a Code Editor
(Optional) ...
Installation of Python

Install PIP on Windows
PIP is a package management system used to install
and manage software packages/libraries written in
Python. PIP stands for Preferred Installer
Program or Pip Installs Packages.

Step 1: Download the get-pip.py (
https://bootstrap.pypa.io/get-pip.py)
file and store it in the same directory as
python is installed.

Step 2: Change the current path of the directory in the
command line to the path of the directory where the
above file exists.

Step 3: get-pip.py is a bootstrapping script that enables
users to install pip in Python environments.
Here, we are installing pip python3. Run the command
given below:
python get-pip.py
Step 4: Now wait through the installation
process. Voila! pip is now installed on your
system.

Verification of the Installation Process
One can easily verify if the pip has been installed correctly by
performing
a version check on the same.
Just go to the command line and execute the following
command:
pip -V
or
pip --version

Characteristics of Python
Python is Interpreted: This means that it is processed at
runtime by the interpreter and you do not need to compile your
program before executing it. This is similar to PERL and PHP.
Python is Interactive: This means that you can actually sit at a
Python prompt and interact with the interpreter directly to
write your programs.
Python is Object-Oriented: This means that Python supports
Object-Oriented style or technique of programming that
encapsulates code within objects.
Python is Beginner's Language: Python is a great language for
the beginner programmers and supports the development of a
wide range of applications, from simple text processing to
WWW browsers to games.

Compiling and interpreting
Many languages require you to compile (translate) your program into a form
that the machine understands.
Python is instead directly interpreted into machine instructions.
compile execute
output
source code
Hello.java
byte code
Hello.class
interpret
output
source code
Hello.py

History of Python:
Python was developed by Guido van Rossum in the late eighties and
early nineties at the National Research Institute for Mathematics and
Computer Science in the Netherlands.
Python is derived from many other languages, including ABC,
Modula-3, C, C++, Algol-68, SmallTalk, and Unix shell and other
scripting languages.
Python is copyrighted, Like Perl, Python source code is now available
under the GNU General Public License (GPL).
Python is now maintained by a core development team at the
institute, although Guido van Rossum still holds a vital role in
directing it's progress.

Python Features
Easy-to-learn: Python has relatively few keywords, simple structure, and
a clearly defined syntax.
Easy-to-read: Python code is much more clearly defined and visible to
the eyes.
Easy-to-maintain: Python's success is that its source code is fairly easy-
to-maintain.
A broad standard library: One of Python's greatest strengths is the bulk
of the library is very portable and cross-platform compatible on UNIX,
Windows, and Macintosh.
Interactive Mode: Support for an interactive mode in which you can
enter results from a terminal right to the language, allowing interactive
testing and debugging of snippets of code.

Python Features (cont’d)
Portable: Python can run on a wide variety of hardware
platforms and has the same interface on all platforms.
Extendable: You can add low-level modules to the Python
interpreter. These modules enable programmers to add to or
customize their tools to be more efficient.
Databases: Python provides interfaces to all major commercial
databases.
GUI Programming: Python supports GUI applications that can be
created and ported to many system calls, libraries, and windows
systems, such as Windows MFC, Macintosh, and the X Window
system of Unix.
Scalable: Python provides a better structure and support for large
programs than shell scripting.

Python Environment
Unix (Solaris, Linux, FreeBSD, AIX, HP/UX, SunOS, IRIX etc.)
Win 9x/NT/2000
Macintosh (PPC, 68K)
OS/2
DOS (multiple versions)
PalmOS
Nokia mobile phones
Windows CE
Acorn/RISC OS
BeOS
Amiga
VMS/OpenVMS
QNX
VxWorks
Psion
Python has also been ported to the Java and .NET virtual machines.

2. Python - Basic Syntax
Interactive Mode Programming:
>>> print "Hello, Python!";
Hello, Python!
>>> 3+4*5;
23

Script Mode Programming :
Invoking the interpreter with a script parameter begins
execution of the script and continues until the script is finished.
When the script is finished, the interpreter is no longer active.
For example, put the following in one test.py, and run,
print "Hello, Python!";
print "I love COMP3050!";
The output will be:
Hello, Python!
I love COMP3050!

Python Identifiers:
A Python identifier is a name used to identify a variable,
function, class, module, or other object. An identifier starts with
a letter A to Z or a to z or an underscore (_) followed by zero or
more letters, underscores, and digits (0 to 9).
Python does not allow punctuation characters such as @, $, and
% within identifiers.
Python is a case sensitive programming language. Thus
Manpower and manpower are two different identifiers in
Python.

Rules for Naming Python Identifiers
•It cannot be a reserved python keyword.
•It should not contain white space.
•It can be a combination of A-Z, a-z, 0-9,
or underscore.
•It should start with an alphabet
character or an underscore ( _ ).
•It should not contain any special
character other than an underscore ( _ ).

Examples of Python Identifiers
Valid identifiers:
•var1
•_var1
•_1_var
•var_1
Invalid Identifiers
•!var1
•1var
•1_var
•var#1
•var 1

Keywords in Python
Python Keywords are some predefined and reserved
words in Python that have special meanings. Keywords
are used to define the syntax of the coding. The
keyword cannot be used as an identifier, function, or
variable name. All the keywords in Python are written in
lowercase except True and False. There are 35 keywords
in Python 3.11

Reserved Words:
and finally not
assert for or
break from pass
class global print
continue if raise
def import return
del in try
elif is while
else lambda with
except True Yield
as nonlocal False
None Await
async
Keywords contain lowercase letters only.

Python Indentation
 Indentation refers to the spaces at the beginning
of a code line.
 Where in other programming languages the
indentation in code is for readability only, the
indentation in Python is very important.
 Python uses indentation to indicate a block of
code.

Python Comments: Importance, Types and
Correct Way to Use
Comments in Python are the lines in the code that are
ignored by the interpreter during the execution of the
program.
Types of Comments in Python
There are three types of comments in Python:
•Single line Comments
•Multiline Comments
•String Literals
•Docstring Comments

1. Single-Line Comments
•Python single-line comment starts with the hashtag
symbol (#) with no white spaces and lasts till the end of
the line.
•If the comment exceeds one line then put a hashtag on
the next line and continue the Python Comment.
•Python’s single-line comments are proved useful for
supplying short explanations for variables, function
declarations, and expressions. See the following code
snippet demonstrating single line comment:

2. Multi-Line Comments
Python does not provide the option for multiline comments
. However, there are different ways through which we can
write multiline comments.
a) Multiline comments using multiple hashtags (#)
We can multiple hashtags (#) to write multiline comments
in Python. Each and every line will be considered as a
single-line comment.

b) Comment Out Multiple Lines in Python using a
Multiline String as a Comment
Python multiline comments can also be enclosed in a
delimiter (“””). Again there should be no white space
between delimiters (“””). They are useful when the comment
text does not fit into one line, therefore needs to span
across lines. This type of string literal gets ignored as it is
not assigned to any variable.

C) In this example, the comments starting
with # are extended to multiple lines using the
backslash () at the end of each line. The backslash
indicates that the comment continues on the next
line. This method can be helpful for improving
code readability when you have lengthy
comments
COPYRIGHT © DR.GARGISHANKAR VERMA , PROFESSOR
KRISHNA VIKASH INSTITUTE OF TECHNOLOGY, RAIPUR

Python Variables
Python Variable is containers that store values. Python is
not “statically typed”. We do not need to declare variables
before using them or declare their type. A variable is
created the moment we first assign a value to it. A Python
variable is a name given to a memory location. It is the
basic unit of storage in a program.

Variables do not need to be declared with any
particular type, and can even change type after they
have been set.

Variables Assignment in Python
we will define a variable in python. Here, clearly we have
assigned a number, a floating point number, and a string to
a variable such as age, salary, and name.
# An integer assignment
age = 45
# A floating point
salary = 1456.8
# A string name = "John"
print(age)
print(salary)
print(name)

Python Assign Values to Multiple
Variables
Python allows assigning a single value to several variables
simultaneously with “=” operators.
For example:

Global and Local Python Variables
Local variables in Python are the ones that are defined
and declared inside a function. We can not call this variable
outside the function.

Global variables in Python are the ones that are defined
and declared outside a function, and we need to use them
inside a function.

Python Data Type

Python Data types are the classification or categorization of
data items. It represents the kind of value that tells what
operations can be performed on a particular data. Since
everything is an object in Python programming,
Python data types are classes and variables are instances
(objects) of these classes.
The following are the standard or built-in data types in
Python:
Numeric
Sequence Type
Boolean
Set
Dictionary
Binary Types

Numbers
Numeric values are stored in numbers. The whole
number, float, and complex qualities have a place with a
Python Numbers datatype. Python offers the type()
function to determine a variable's data type. The instance
() capability is utilized to check whether an item has a
place with a specific class.
When a number is assigned to a variable, Python
generates Number objects. For instance,

•Int: Whole number worth can be any length, like
numbers 10, 2, 29, - 20, - 150, and so on. An integer can
be any length you want in Python. Its worth has a place
with int.
•Float: Float stores drifting point numbers like 1.9, 9.902,
15.2, etc. It can be accurate to within 15 decimal places.
•Complex: An intricate number contains an arranged
pair, i.e., x + iy, where x and y signify the genuine and
non-existent parts separately. The complex numbers like
2.14j, 2.0 + 2.3j, etc.

Sequence Type
String
The sequence of characters in the quotation marks can be
used to describe the string. A string can be defined in
Python using single, double, or triple quotes.
String dealing with Python is a direct undertaking since
Python gives worked-in capabilities and administrators to
perform tasks in the string.
When dealing with strings, the operation "hello"+" python"
returns "hello python," and the operator + is used to
combine two strings.
Because the operation "Python" *2 returns "Python," the
operator * is referred to as a repetition operator.

List
Lists in Python are like arrays in C, but lists can contain
data of different types. The things put away in the
rundown are isolated with a comma (,) and encased inside
square sections [].
To gain access to the list's data, we can use slice [:]
operators. Like how they worked with strings, the list is
handled by the concatenation operator (+) and the
repetition operator (*)

Tuple
In many ways, a tuple is like a list. Tuples, like lists, also contain a
collection of items from various data types. A parenthetical space ()
separates the tuple's components from one another.
Because we cannot alter the size or value of the items in a tuple, it is
a read-only data structure.
Let's look at a straightforward tuple in action.

Dictionary
A dictionary is a key-value pair set arranged in any order.
It stores a specific value for each key, like an associative
array or a hash table. Value is any Python object, while the
key can hold any primitive data type.
The comma (,) and the curly braces are used to separate
the items in the dictionary.

Boolean
True and False are the two default values for the Boolean
type. These qualities are utilized to decide the given assertion
valid or misleading. The class book indicates this. False can be
represented by the 0 or the letter "F," while true can be
represented by any value that is not zero.

Set
The data type's unordered collection is Python Set. It is
iterable, mutable(can change after creation), and has
remarkable components. The elements of a set have no set
order; It might return the element's altered sequence.
Either a sequence of elements is passed through the curly
braces and separated by a comma to create the set or the
built-in function set() is used to create the set. It can contain
different kinds of values.

Python Operators
The operator is a symbol that performs a specific operation
between two operands, according to one definition.
Operators serve as the foundation upon which logic is
constructed in a program in a particular programming
language. In every programming language, some operators
perform several tasks. Same as other languages, Python
also has some operators, and these are given below -
•Arithmetic operators
•Comparison operators
•Assignment Operators
•Logical Operators
•Bitwise Operators
•Membership Operators
•Identity Operators

Operator Description
+ (Addition) It is used to add two operands. For example, if a = 10, b
= 10 => a+b = 20
- (Subtraction) It is used to subtract the second operand from the first
operand. If the first operand is less than the second
operand, the value results negative. For example, if a =
20, b = 5 => a - b = 15
/ (divide) It returns the quotient after dividing the first operand
by the second operand. For example, if a = 20, b = 10
=> a/b = 2.0
* (Multiplication) It is used to multiply one operand with the other. For
example, if a = 20, b = 4 => a * b = 80
% (reminder) It returns the reminder after dividing the first operand
by the second operand. For example, if a = 20, b = 10
=> a%b = 0
** (Exponent) As it calculates the first operand's power to the second
operand, it is an exponent operator.
// (Floor division) It provides the quotient's floor value, which is obtained
by dividing the two operands.
Arithmetic Operators
Arithmetic operators used between two operands for a particular operation. There
are many arithmetic operators. It includes the exponent (**) operator as well as the
+ (addition), - (subtraction), * (multiplication), / (divide), % (reminder), and // (floor
division) operators.
Consider the following table for a detailed explanation of arithmetic operators.

Comparison operator
Comparison operators mainly use for comparison
purposes. Comparison operators compare the values of the
two operands and return a true or false Boolean value in
accordance. The example of comparison operators are ==, !
=, <=, >=, >, <. In the below table, we explain the works of
the operators.
== If the value of two operands is equal, then the condition becomes true.
!= If the value of two operands is not equal, then the condition becomes true.
<= The condition is met if the first operand is smaller than or equal to the second
operand.
>= The condition is met if the first operand is greater than or equal to the second
operand.
> If the first operand is greater than the second operand, then the condition becomes
true.
< If the first operand is less than the second operand, then the condition becomes
true.

Assignment Operators
Using the assignment operators, the right expression's
value is assigned to the left operand. There are some
examples of assignment operators like =, +=, -=, *=, %=, **=,
//=. In the below table, we explain the works of the
operators.
= It assigns the value of the right expression to the left operand.
+= By multiplying the value of the right operand by the value of the left operand, the left operand receives a
changed value. For example, if a = 10, b = 20 => a+ = b will be equal to a = a+ b and therefore, a = 30.
-= It decreases the value of the left operand by the value of the right operand and assigns the modified value
back to left operand. For example, if a = 20, b = 10 => a- = b will be equal to a = a- b and therefore, a = 10.
*= It multiplies the value of the left operand by the value of the right operand and assigns the modified value
back to then the left operand. For example, if a = 10, b = 20 => a* = b will be equal to a = a* b and
therefore, a = 200.
%= It divides the value of the left operand by the value of the right operand and assigns the reminder back to
the left operand. For example, if a = 20, b = 10 => a % = b will be equal to a = a % b and therefore, a = 0.
**= a**=b will be equal to a=a**b, for example, if a = 4, b =2, a**=b will assign 4**2 = 16 to a.
//= A//=b will be equal to a = a// b, for example, if a = 4, b = 3, a//=b will assign 4//3 = 1 to a.

Bitwise Operators
The two operands' values are processed bit by bit by the
bitwise operators. The examples of Bitwise operators are
bitwise OR (|), bitwise AND (&), bitwise XOR (^), negation
(~), Left shift (<<), and Right shift (>>). Consider the case
below. Operator Description
& (binary and) A 1 is copied to the result if both bits in two
operands at the same location are 1. If not, 0
is copied.
| (binary or) The resulting bit will be 0 if both the bits are
zero; otherwise, the resulting bit will be 1.
^ (binary xor) If the two bits are different, the outcome bit
will be 1, else it will be 0.
~ (negation) The operand's bits are calculated as their
negations, so if one bit is 0, the next bit will
be 1, and vice versa.
<< (left shift) The number of bits in the right operand is
multiplied by the leftward shift of the value
of the left operand.
>> (right shift) The left operand is moved right by the
number of bits present in the right operand.

Logical Operators
The assessment of expressions to make decisions typically
uses logical operators. The examples of logical operators
are and, or, and not. In the case of logical AND, if the first
one is 0, it does not depend upon the second one. In the
case of logical OR, if the first one is 1, it does not depend on
the second one. Python supports the following logical
operators. In the below table, we explain the works of the
logical operators.
and The condition will also be true if the expression is true. If the two
expressions a and b are the same, then a and b must both be
true.
or The condition will be true if one of the phrases is true. If a and b
are the two expressions, then an or b must be true if and is true
and b is false.
not If an expression a is true, then not (a) will be false and vice versa.

in If the first operand cannot be found in the
second operand, it is evaluated to be true (list,
tuple, or dictionary).
not in If the first operand is not present in the second
operand, the evaluation is true (list, tuple, or
dictionary).
Membership Operators
The membership of a value inside a Python data
structure can be verified using Python membership
operators.
The result is true if the value is in the data structure;
otherwise, it returns false.

Taking input in Python
Python input() function is used to take user input.
By default, it returns the user input in form of a string.
Syntax: input(prompt)
name = input("Enter your name: ")
print("Hello,", name, "! Welcome!")
Enter your name: GeeksforGeeks
Hello, GeeksforGeeks ! Welcome!

Intger Numbers in Python
The code prompts the user to input an integer
representing the number of roses, converts the input to
an integer using typecasting, and then prints the integer
value.
# Taking input as int
# Typecasting to int
n = int(input("How many roses?: "))
print(n)
How many roses?: 8
8

How to Print Float/Decimal Number in Python
# Taking input as float
# Typecasting to float
price = float(input("Price of each rose?: "))
print(price)
Price of each rose?: 50.30
50.3

Conditional Input from user in Python
In this example, the program prompts the user to enter their
age. The input is converted to an integer using the int()
function. Then, the program uses conditional statements to
check the age range and prints a message based on whether
the user is a minor, an adult, or a senior citizen.

# Prompting the user for input
age_input = input("Enter your age: ")
# Converting the input to an integer
age = int(age_input)
# Checking conditions based on user input
if age < 0:
print("Please enter a valid age.")
elif age < 18:
print("You are a minor.")
elif age >= 18 and age < 65:
print("You are an adult.")
else:
print("You are a senior citizen.")

Take Multiple Input in Python
The code takes input from the user in a single line, splitting
the values entered by the user into separate variables for
each value using the split() method. Then, it prints the
values with corresponding labels, either two or three,
based on the number of inputs provided by the user.
# taking two inputs at a time
x, y = input("Enter two values: ").split()
print("Number of boys: ", x)
print("Number of girls: ", y)
# taking three inputs at a time
x, y, z = input("Enter three values: ").split()
print("Total number of students: ", x)
print("Number of boys is : ", y)
print("Number of girls is : ", z)

Enter two values: 5 10
Number of boys: 5
Number of girls: 10
Enter three values: 5 10 15
Total number of students: 5
Number of boys is : 10
Number of girls is : 15

Formatting the Output
Output formatting in Python with various techniques
including the format() method, manipulation of the sep
and end parameters, f-strings, and the versatile %
operator. These methods enable precise control over how
data is displayed, enhancing the readability and
effectiveness of your Python programs.

Example 1: Using Format()
amount = 150.75
print("Amount: ${:.2f}".format(amount))
Amount: $150.75

Example 2: Using sep and end parameter
# end Parameter with '@'
print("Python", end='@')
print("GeeksforGeeks")
# Seprating with Comma
print('G', 'F', 'G', sep='')
# for formatting a date
print('09', '12', '2016', sep='-')
# another example
print('pratik', 'geeksforgeeks', sep='@')
Python@GeeksforGee
ks
GFG
09-12-2016
pratik@geeksforgee
ks

Example 3: Using f-string
name = 'Tushar'
age = 23
print(f"Hello, My name is {name} and I'm {age} years old.")
Hello, My name is Tushar and I'm 23 years old.

Example 4: Using % Operator
We can use ‘%’ operator. % values are replaced with zero
or more value of elements. The formatting using % is
similar to that of ‘printf’ in the C programming language.
•%d –integer
•%f – float
•%s – string
•%x –hexadecimal
•%o – octal

# Taking input from the user
num = int(input("Enter a value: "))
add = num + 5
# Output
print("The sum is %d" %add)
Enter a value: 50 The sum is 55

# Simple Python program to understand the arithmetical oper
ator addition
# Here, we are storing the first input numbers in num1
num1 = input('Enter first number: ')
# Here, we are storing the second input numbers in num2
num2 = input('Enter second number: ')
# Here, we are declaring a variable sum to store the result
# Here, we are using the arithmetical operator to add the two
numbers
sum = float(num1) + float(num2)
# Here, we are printing the sum of the given two numbers
print('The sum of {0} and {1} is {2}'.format(num1, num2, sum))

Enter first number: 10
Enter second number: 20
The sum of 10 and 20 is 30.0

Add Two Numbers in Python
There are many methods to add two number in Python:
•Using “+” operator
•Defining a function that adds two number
•Using operator.add method
•Using lambda function
•Using Recursive function

Add Two Numbers with “+” Operator
Here num1 and num2 are variables and we are going to
add both variables with the +
# Python3 program to add two numbers
num1 = 15
num2 = 12
# Adding two nos
sum = num1 + num2
# printing values
print("Sum of", num1, "and", num2 , "is", sum)
Sum of 15 and 12 is 27

Add Two Numbers with User Input
In the below program to add two numbers in Python,
the user is first asked to enter two numbers, and the
input is scanned using the Python input() function and
stored in the variables number1 and number2.
Then, the variable’s number1 and number2 are added
using the arithmetic operator +, and the result is
stored in the variable sum.

number1 = input("First number: ")
number2 = input("nSecond number: ")
# Adding two numbers
# User might also enter float numbers
sum = float(number1) + float(number2)
# Display the sum
# will print value in float
print("The sum of {0} and {1} is {2}" .format(number1, number2, sum))
First number: 13.5 Second number: 1.54
The sum of 13.5 and 1.54 is 15.04

Add Two Numbers in Python Using Function
This program show adding two numbers in Python
using function. We can define a function that accepts
two integers and returns their sum.
#To define a function that take two integers
# and return the sum of those two numbers
def add(a,b):
return a+b
#initializing the variables
num1 = 10
num2 = 5
#function calling and store the result into sum_of_twonumbers
sum_of_twonumbers = add(num1,num2)
#To print the result
print("Sum of {0} and {1} is {2};" .format(num1,num2, sum_of_twonumbers))
Sum of 10 and 5 is 15;

Add Two Numbers Using operator.add() Method
Initialize two variables num1, and num2. Find sum using
the operator.add() by passing num1, and num2 as
arguments and assign to su. Display num1,num2 and sum
num1 = 15
num2 = 12
# Adding two nos
import operator
su = operator.add(num1,num2)
# printing values
print("Sum of {0} and {1} is {2}" .format(num1,num2, sum))
Sum of 15 and 12 is 27

String upper()
# all alphabets should be lowercase
string = "Th!s Sh0uLd B3 uPp3rCas3!"
print(string.upper())
# example string
string = "this should be uppercase!"
print(string.upper())
# string with numbers
THIS SHOULD BE UPPERCASE!
TH!S SH0ULD B3 UPP3RCAS3!

# first string
firstString = "python is awesome!"
# second string
secondString = "PyThOn Is AwEsOmE!"
if(firstString.upper() == secondString.upper()):
print("The strings are same.")
else:
print("The strings are not same.")
The strings are same.

# example string
string = "THIS SHOULD BE LOWERCASE!"
print(string.lower())
# string with numbers
# all alphabets should be lowercase
string = "Th!s Sh0uLd B3 L0w3rCas3!"
print(string.lower())
this should be lowercase!
th!s sh0uld b3 l0w3rcas3!
String lower()

# first string
firstString = "PYTHON IS AWESOME!"
# second string
secondString = "PyThOn Is AwEsOmE!"
if(firstString.lower() == secondString.lower()):
print("The strings are same.")
else:
print("The strings are not same.")
The strings are same.

String casefold()
The casefold() method converts all characters of the string into
lowercase letters and returns a new string.
text = "pYtHon"
# convert all characters to lowercase
lowercased_string = text.casefold()
print(lowercased_string)
# Output: python

String swapcase()
sentence1 = "THIS SHOULD ALL BE LOWERCASE."
# converts uppercase to lowercase
print(sentence1.swapcase())
sentence2 = "this should all be uppercase."
# converts lowercase to uppercase
sentence3 = "ThIs ShOuLd Be MiXeD cAsEd."
# converts lowercase to uppercase and vice versa

this should all be lowercase.
THIS SHOULD ALL BE UPPERCASE.
tHiS sHoUlD bE mIxEd CaSeD.

Implementing Switch in Python using elif ladder
day = input("Enter the day of the week: ").capitalize()
if day == "Saturday" or day == "Sunday":
print(f"{day} is a weekend.")
elif day in ["Monday", "Tuesday", "Wednesday", "Thursday",
"Friday"]:
print(f"{day} is a weekday.")
else:
print("That's not a valid day of the week.")
Saturday is a weekend

def num_in_words(no):
if(no==1):
print("One")
elif(no==2):
print("Two")
elif(no==3):
print("Three")
else:
print("Give input of numbers from 1 to 3")
num_in_words(3)
num_in_words(4.5)
Three
Give input of numbers from 1 to 3

Implementing Python Switch using Dictionary
We can use a dictionary to implement the switch case. We know
that the dictionary holds the key-value pairs. It can have the
keys as the condition/ element to be checked and the values as
the elements to be printed or the functions to be executed.
def vowel(num):
switch={
1:'a',
2:'e',
3:'i',
4:'o',
5:'u'
}
return switch.get(num,"Invalid input")
vowel(3)
vowel(0)

‘i’
‘Invalid input’

implementing switch case using the dictionary with
functions as values:
def add():
return n+m
def subs():
return n-m
def prod():
return n*m
def div():
return m/n
def rem():
return m%n
def operations(op):
switch={
'+': add(),
'-': subs(),
'*': prod(),
'/': div(),
'%': rem(), }
return switch.get(op,'Choose one of the following operator:+,-,*,/,%')
operations('*')
operations('^')

36
‘Choose one of the following
operator:+,-,*,/,%’

Implementing Python Switch using Class

class Month(object):
def month_1(self):
print("January")
def month_2(self):
print("February")
def month_3(self):
print("March")
def month_4(self):
print("April")
def month_5(self):
print("May")
def month_6(self):
print("June")
def month_7(self):
print("July")
def month_8(self):
print("August")
def month_9(self):
print("September")
def month_10(self):
print("October")
def month_11(self):
print("November")
def month_12(self):
print("December")
def getMonth(self,no):
name_of_method="month_"+str(no)
method=getattr(self,name_of_method,lambda :'Give an input as an integer from 1 to 12')
return method()
)

mo=Month()
mo.getMonth(5)
mo.getMonth(0.5
May
‘Give an input as an integer from 1 to 12’

day = input("Enter the day of the week: ").capitalize()
match day:
case "Saturday" | "Sunday":
print(f"{day} is a weekend.")
case "Monday" | "Tuesday" | "Wednesday" | "Thursday" |
"Friday":
print(f"{day} is a weekday.")
case _:
print("That's not a valid day of the week.")
Match and Case in Python
Monday is a weekday.

Advanced Use Cases of Match and Case in Python
animal = "Eagle"
match animal:
case "Eagle" | "Parrot":
print("Bird")
case "Lion" | "Tiger":
print("Mammal")
case "Python" | "Crocodile":
print("Reptile")
case _:
print("Unknown Class")

Python Program to Find the Roots of a
Quadratic Equation
print("Equation: ax^2 + bx + c ")
a=int(input("Enter a: "))
b=int(input("Enter b: "))
c=int(input("Enter c: "))
d=b**2-4*a*c
d1=d**0.5
if(d<0):
print("The roots are imaginary. ")
else: r1=(-b+d1)/2*a r2=(-b-d1)/2*a
print("The first root:
",round(r1,2))
print("The second root:
",round(r2,2))

Case 1: Equation: ax^2 + bx + c
Enter a: 1
Enter b: -5
Enter c: 6
The first root: 3.0
The second root: 2.0
Case 2: Equation: ax^2 + bx + c
Enter a: 1
Enter b: 5
Enterc: 10
The roots are imaginary.

Python File Handling
Python supports the file-handling process. Till now, we
were taking the input from the console and writing it back
to the console to interact with the user. Users can easily
handle the files, like read and write the files in Python. In
another programming language, the file-handling process
is lengthy and complicated. But we know Python is an easy
programming language. So, like other things, file handling
is also effortless and short in Python.

Hence, a file operation can be done in the following order.
•Open a file
•Read or write - Performing operation
•Close the file

Opening a file
A file operation starts with the file opening. At first, open the
File then Python will start the operation. File opening is done
with the open() function in Python.
This function will accepts two arguments, file name and access
mode in which the file is accessed.
When we use the open() function, that time we must be
specified the mode for which the File is opening.
The function returns a file object which can be used to
perform various operations like reading, writing, etc.
Syntax:
The syntax for opening a file in Python is given below -
file object = open(<file-name>, <access
mode>, <buffering>)

SN Access
mode
Description
1 r r means to read. So, it opens a file for read-only operation.
The file pointer exists at the beginning. The file is by default
open in this mode if no access mode is passed.
2 rb It opens the file to read-only in binary format. The file
pointer exists at the beginning of the file.
3 r+ It opens the file to read and write both. The file pointer
exists at the beginning of the file.
4 rb+ It opens the file to read and write both in binary format. The
file pointer exists at the beginning of the file.
5 w It opens the file to write only. It overwrites the file if
previously exists or creates a new one if no file exists with
the same name. The file pointer exists at the beginning of
the file.
6 wb It opens the file to write only in binary format. It overwrites
the file if it exists previously or creates a new one if no file
exists. The file pointer exists at the beginning of the file.
7 w+ It opens the file to write and read both. It is different from
r+ in the sense that it overwrites the previous file if one
exists whereas r+ doesn't overwrite the previously written

8 wb+ It opens the file to write and read both in
binary format. The file pointer exists at the
beginning of the file.
9 a It opens the file in the append mode. The file
pointer exists at the end of the previously
written file if exists any. It creates a new file if
no file exists with the same name.
10 ab It opens the file in the append mode in binary
format. The pointer exists at the end of the
previously written file. It creates a new file in
binary format if no file exists with the same
name.
11 a+ It opens a file to append and read both. The
file pointer remains at the end of the file if a
file exists. It creates a new file if no file exists
with the same name.
12 ab+ It opens a file to append and read both in
binary format. The file pointer remains at the
end of the file.

Python Program to Read the
Contents of the File
a=str(input("Enter the name of the file with .txt
extension:"))
file2=open(a,'r')
line=file2.readline()
while(line!=""):
print(line)
line=file2.readline()
file2.close()
1.User must enter a file name.
2. The file is opened using the open() function in the read
mode.
3.The readline() outside the while loop is used to read the
first line of the file.
4. Inside the loop, the first line is first printed and then the
remaining lines are read and subsequently printed.
5. This continues this the end of file.
6. The file is then closed.

Python Program to Append the Content of
One File to the End of Another File
name1 = input("Enter file to be read from: ")
name2 = input("Enter file to be appended to: ")
fin = open(name1, "r")
data2 = fin.read()
fin.close()
fout = open(name2, "a")
fout.write(data2)
fout.close()

1. User must enter the name of the file to be read from
and the file to append into.
2. The file to be read is opened using open() function in the
read mode.
3. The contents of the file read using read() function is
stored in a variable and then the file is closed.
3. The file to append the data to is opened in the append
mode and the data stored in the variable is written into the
file.
4. The second file is then closed..

import os
def create_file(filename):
try:
with open(filename, 'w') as f:
f.write('Hello, world!n')
print("File " + filename + " created successfully.")
except IOError:
print("Error: could not create file " + filename)

def read_file(filename):
try:
with open(filename, 'r') as f:
contents = f.read()
print(contents)
except IOError:
print("Error: could not read file " + filename)

def rename_file(filename, new_filename):
try:
os.rename(filename, new_filename)
print("File " + filename + " renamed to " + new_filename + "
successfully.")
except IOError:
print("Error: could not rename file " + filename)

def delete_file(filename):
try:
os.remove(filename)
print("File " + filename + " deleted successfully.")
except IOError:
print("Error: could not delete file " + filename)

if __name__ == '__main__':
filename = "example.txt"
new_filename = "new_example.txt"
create_file(filename)
read_file(filename)
append_file(filename, "This is some additional text.n")
read_file(filename)
rename_file(filename, new_filename)
read_file(new_filename)
delete_file(new_filename

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