DEV Community: varatharajan

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varatharajan — Thu, 28 Nov 2024 14:21:06 +0000

while loop - task

varatharajan — Thu, 28 Nov 2024 08:27:37 +0000

Here are some while loop questions focused on numbers for practice:

Basic Problems :
Print Numbers :
Write a program to print numbers from 1 to 10 using a while loop.
input :

def print_number(no):
    num=1
    while num<=no:
        print(num,end=' ')
        num+=1

print_number(10)

no = 1
while no<=10:
    print(no, end=' ')
    no+=1

output :
1 2 3 4 5 6 7 8 9 10
Sum of N Numbers :
Write a program to calculate the sum of the first NN natural numbers using a while loop.
input :

def sum_of_natural_numbers(no):
    sum = 0
    num = 1  
    while num <= no:
        sum =sum + num  
        num += 1  
    return sum

no = int(input("Enter a number: "))

result = sum_of_natural_numbers(no)
print("The sum of the first", no, "natural numbers is:", result)

output :
Enter a number: 5 The sum of the first 5 natural numbers is: 15
Even Numbers
Write a program to print all even numbers between 1 and 50 using a while loop.
input :

def even_numbers(num):

    no = 2
    while no<=num:
        print(no, end=' ')
        no+=2

even_numbers(50)

output:
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50
Odd Numbers
Write a program to print all odd numbers between 1 and NN.
input:

def print_odd_number(no):
    num=1
    while num<=no:
        print(num, end=" ")
        num+=2
    return no
no=int(input("Enter the number:"))
print_odd_number(no)

output :
Enter the number:50 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49
Reverse Count
Write a program to print numbers from 20 to 1 in reverse order using a while loop.
input:

def print_reverse_number(no):
    num=20
    while num>=no:
        print(num, end=" ")
        num-=1
print_reverse_number(1)

output:
20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
Intermediate Problems:

Factorial Calculation
Write a program to calculate the factorial of a given number using a while loop.
input:

def factorial(no):
    num=1
    factorial=1
    while num<=no:
        factorial=factorial*num
        num+=1
    return factorial

no = int(input("Enter the number : "))
print(factorial(no))

output:
Enter the number : 4 24

looping

varatharajan — Tue, 26 Nov 2024 09:10:25 +0000

while :

Task :

1) 1 2 3 4 5 6 7 8 9 10
2) 10 9 8 7 6 5 4 3 2 1
3) 1 3 5 7 9
4) 2 4 6 8 10
5) 3 6 9

input :

#1 2 3 4 5 6 7 8 9 10
no = 1
while no<=10:
    print(no, end=' ')
    no+=1

print()

# 10 9 8 7 6 5 4 3 2 1
no = 10
while no>=1:
    print(no, end=' ')
    no-=1

print()

# 1 3 5 7 9 
no = 1
while no<=10:
    print(no, end=' ')
    no+=2

print()

#2 4 6 8 10
no=2
while no<=10:
    print(no, end=' ')
    no+=2

print()

# 3 6 9
no = 3
while no<=10:
    print(no, end=' ')
    no+=3

output :
1 2 3 4 5 6 7 8 9 10 10 9 8 7 6 5 4 3 2 1 1 3 5 7 9 2 4 6 8 10 3 6 9
using '*'
input

# 3 6 9 12 15 18 21
no = 1
while no<=7:
    print(no*3, end=' ')
    no+=1

output
3 6 9 12 15 18 21
Task :
1 * 5 = 5
2 * 5 = 10
3 * 5 = 15

input

no = 1 
while no<=10:
    result = no*5
    print(f"{no}*5 = {result}")
    no+=1

output
1*5 = 5 2*5 = 10 3*5 = 15 4*5 = 20 5*5 = 25 6*5 = 30 7*5 = 35 8*5 = 40 9*5 = 45 10*5 = 50
example :

1*2=2
3*2=6
5*2=10
7*2=14
9*2=18

input

no = 1
while no<=10:
    result=no*2
    print(f"{no}*2={result}")
    no+=2

output
1*2=2 3*2=6 5*2=10 7*2=14 9*2=18
example :

#1 3 5 7 9 2 4 6 8 10

no = 1
while no<=10:
    print(no, end = ' ')
    if no==9:
       no=0
    no+=2

output
1 3 5 7 9 2 4 6 8 10

while loop, predefind modules

varatharajan — Sun, 24 Nov 2024 12:14:27 +0000

The while Loop

With the while loop we can execute a set of statements as long as a condition is true.

input

i = 1
while i < 6:
  print(i)
  i = i+1

output
1 2 3 4 5
For writing multiple "if"conditions we can use "while"loop for repeated condition.
example :
To get this output 1 1 1 1 1 we have various syntax but we can use if and while now.

case 1 :

#using if condition

count = 1
if count<=5:
    print(1, end=' ')
    count=count+1 #count = 2
if count<=5:
    print(1, end=' ')
    count=count+1 # count = 3

if count<=5:
    print(1, end=' ')
    count=count+1 # count = 4

if count<=5:
    print(1, end=' ')
    count=count+1 # count = 5

if count<=5:
    print(1, end=' ')
    count=count+1 # count = 6

output
1 1 1 1 1
case 2 :

count = 1
while count<=5:
    print(1, end=' ')
    count=count+1 #count = 2

output
1 1 1 1 1

Task 1:

Create a python module called Bank.
Add functions: deposit(amount), withdraw(amount)
Create one more python module called Customer
From customer module, call deposit and withdraw functions of Bank module.

#bank.py

def deposit(amount):
    print("Total deposit amount is ",amount)
    return(amount)

def withdraw(amount):
    print("Total withdrawal amount is ",amount)
    return(amount)

#customer.py

import Bank

total_deposit=Bank.deposit(200000)
total_withdrawal=Bank.withdraw(20000)

print("Bank balance is ",(total_deposit-total_withdrawal))

output

Total deposit amount is 200000 Total withdrawal amount is 20000 Bank balance is 180000

predefined modules:

random :

input

import random
otp = random.randint(0,9999)
print(otp)

output

4321 3185 4238

math

input

import math
print(math.sqrt(9))

output
3.0

datetime

input

from datetime import datetime

now = datetime.now()
print("Current Date and Time:", now)

output

Current Date and Time: 2024-11-25 13:31:37.449457

Modules

varatharajan — Fri, 22 Nov 2024 08:31:42 +0000

Modules :

Every python file is a module.
To create a module just save the code you want in a file with the file extension .py
Modules have special variables.
example:
file (file---->The file path of the module)
name (name---->Name of the module)
doc (documtation string of the module) ("""abcd""" or '''abcd''')

input

#current module name - vara.py

""" The nature is beautiful"""
print(__name__) 
print(__file__)
print(__doc__)

output
__main__ C:\Users\Lakshmipriya\OneDrive\Desktop\VARATHARAJAN\vara.py The nature is beautiful
The import statement
The import statement in Python is used to bring code from one module into another.
example :

#num.py

def add(no1,no2):
    print(no1+no2)


def subtract(no1,no2):
    print(no1-no2)


def multiply(no1,no2):
    print(no1*no2)


def divide(no1,no2):
    print(no1/no2)

input

#vara.py

import num

num.add(10,20)
num.subtract(50,25)

*output *

30 25
If we need specific functions alone from one module means then no need to import whole module,instead we can use "from" to take specific function

example
input

#vara.py

from num import add,subtract

add(10,20)
subtract(50,25)
multiply(10,20) #this function is not defind

output

30 25 Traceback (most recent call last): File "C:\Users\Lakshmipriya\OneDrive\Desktop\VARATHARAJAN\vara.py", line 7, in <module> multiply(10,20) NameError: name 'multiply' is not defined
help()
To see all details about the particular module like functions, file location, including documentation string.

num.py

''' This module contain some functions'''

def add(no1,no2):
print(no1+no2)

def subtract(no1,no2):
print(no1-no2)

input

import num
print(help(num))

output

NAME
    num - This module contain some functions

FUNCTIONS
    add(no1, no2)

    divide(no1, no2)

    multiply(no1, no2)

    subtract(no1, no2)

FILE
    c:\users\lakshmipriya\onedrive\desktop\varatharajan\num.py


None

for loop & If,else condition

varatharajan — Wed, 20 Nov 2024 10:22:06 +0000

For loop

The for Loops in Python are a special type of loop statement that is used for sequential traversal. Python for loop is used for iterating over an iterable like a String, Tuple, List, Set, or Dictionary.

example :

name = 'varatharajan'

for alphabet in name:
    print(alphabet, end=' ')

result

v a r a t h a r a j a n

if,else

The if statement is the most simple decision-making statement. It is used to decide whether a certain statement or block of statements will be executed or not.
The elif keyword is Python's way of saying "if the previous conditions were not true, then try this condition".

example 1 :

a = 33
b = 200
if b > a:
  print("b is greater than a")

result
b is greater than a
example 2 :

txt = '12a4'

for num in txt:
    if num>='0' and num<='9':
        print(num,end=' ')
    else:
        print('Not Decimal',end=' ')

result
1 2 Not Decimal 4

Task :
name = input("Enter Name: ")
Lakshmi pritha
Guru prasanna
Guhanraja
Varatharajan

1: Names starting with letter 'G'
2: Names endings with 'a'
3: Names having space in between
4: Names having more than 9 letters

input

name1 = input("Enter the first name: ")
name2 = input("Enter the second name: ")
name3 = input("Enter the third name: ")
name4 = input("Enter the fourth name: ")
name = [name1, name2, name3, name4]

# Check if names start with 'G'
for letter in name:
    if letter[0]=='G':
        print(letter)

# Check if names end with 'a'
for alphabet in name:
    if alphabet[-1]=='a':
        print(alphabet)

# Check if names contain a space
for alpha in name:
    for space in alpha:
        if space==' ':
            print(alpha)

# Check if names are longer than 9 characters
for character in name:
    if len(character)>9:
        print(character)

Output

Enter the first name: Varatharajan Enter the second name: Guru prasanna Enter the third name: Lakshmi pritha Enter the fourth name: Guhanraja Guru prasanna Guhanraja Guru prasanna Lakshmi pritha Guhanraja Guru prasanna Lakshmi pritha Varatharajan Guru prasanna Lakshmi pritha

Task

input

name = input('enter your name :')
print(name)


for alphabet in name:
    print(alphabet,end=' ')

print()

for alphabet in name:
    print(alphabet,end='*')

print()

for alphabet in name:
    print(alphabet)

Output

enter your name :varatha varatha v a r a t h a v*a*r*a*t*h*a* v a r a t h a

string in Python

varatharajan — Tue, 19 Nov 2024 08:37:23 +0000

Strings
Strings in python are surrounded by either single quotation marks, or double quotation marks.
'hello' is the same as "hello".

You can display a string literal with the print() function:
example

name = 'varatharajan'
name = "varatharajan"
print(name)
print(name)

result
`
varatharajan
varatharajan

`
Multiline Strings

You can assign a multiline string to a variable by using three quotes:
example1:


city = '''Madurai's Jigarthanda is very famous'''
print(city)

result
Madurai's Jigarthanda is very famous

example2:

address = """3, kosakulam,
          madurai - 17"""

print(address)

result

3, kosakulam, madurai - 17

Objects

Python is an object oriented programming language.
Almost everything in Python is an object, with its properties and methods.
Every object has its own memory space.
In Python, the id() function returns the unique memory address of the object passed to it.

example :

name = 'Varatharajan'
degree = 'Bsc.Phy,'
height = 165
sunday = False
print(id(name))
print(id(degree))
print(id(height))
print(id(sunday))

result
1855594568496 1855594568304 1855593256304 140732337605512

1.String is immutable.
2.String is index-based
3.String starts from 0

Index/subscript:

A string is a sequence of characters, so indexing can be used to access individual characters.

example 1 :

name = 'varatharajan'

print(name[0])
print(name[1])
print(name[2])
print(name[3])
print(name[4])
print(name[5])
print(name[6])
print(name[7])
print(name[8])
print(name[9])
print(name[10])
print(name[11])

result
v a r a t h a r a j a n

example 2 :

name = 'varatharajan'

print(name[0],end=' ')
print(name[1],end=' ')
print(name[2],end=' ')
print(name[3],end=' ')
print(name[4],end=' ')
print(name[5],end=' ')
print(name[6],end=' ')

result
v a r a t h a
example 3 :

name = 'varatharajan'

# first letter
print(name[0])
#last letter
print(name[11])
#first letter 'v'
if name[0] == 'v':
    print("yes starts with v")
#last letter 'a'
if name[11] == 'n':
    print("yes ends with n")
#all letters with single space in same line
print(name[0], end=' ')
print(name[1], end=' ')
print(name[2], end=' ')
print(name[3], end=' ')
print(name[4], end=' ')
print(name[5], end=' ')
print(name[6], end=' ')
print(name[7], end=' ')
print(name[8], end=' ')
print(name[9], end=' ')
print(name[10], end=' ')
print(name[11], end=' ')
#middle letter ??

length = len(name) #12

print(name[length//2])

result
v n yes starts with v yes ends with n v a r a t h a r a j a n a

Programs

varatharajan — Mon, 18 Nov 2024 03:35:00 +0000

*SSLC mark and percentage calculator program in Python
*

tamil = input("Tamil Mark please: ")
english = input("English Mark please: ")
maths = input("Maths Mark please: ")
science = input("Science Mark please: ")
social = input("Social Mark please: ")
result = int(tamil) + int(english) + int(maths) + int(science) + int(social)
print("total mark is:",result)
print("percentage is:",(result)*(100/500),'%')

result
`
Tamil Mark please: 90
English Mark please: 85
Maths Mark please: 85
Science Mark please: 90
Social Mark please: 90
total mark is: 440
percentage is: 88.0 %

BMI calculator program in Python

Weight = int(input("Enter your weight: "))
Hight = float(input("Enter your height: "))

def bmiCal(Weight,Height):

    bmi = Weight/float(Height*Height)
    result = ''
    if bmi < 18.50:
        result = 'under weight' 
    elif bmi >=18.50 and bmi <= 24.9:
        result = 'healthy weight'     
    elif bmi >=25 and bmi <= 29.9:
        result = 'over weight'
    elif bmi >=30:
        result = 'obesity'

    return result


print(bmiCal(Weight,Hight))

result
Enter your weight: 60 Enter your height: 1.65 healthy weight

EB calculator
simple calculate

units = int(input("Enter no of units consumed :"))
price = int(input("Enter the price per unit : "))



def calculate(units,price):
    return units*price


result = calculate(units,price)

print("Total price is : ",result )

result

Enter no of units consumed :100 Enter the price per unit : 3 Total price is : 300

Day 3 - Python

varatharajan — Thu, 14 Nov 2024 09:58:47 +0000

Built-in Data Types :
**
In programming, data type is an important concept.

Variables can store data of different types, and different types can do different things.

Text Type: str
Numeric Types: int, float, complex
Sequence Types: list, tuple, range
Mapping Type: dict
Set Types: set, frozenset
Boolean Type: bool
Binary Types: bytes, bytearray, memoryview
None Type: NoneType

for example

no1 = 5
print(no1)
print(type(no1))

no2 = ("get a value from user")
print(no2)
print(type(no2))

no3 = 5.5
print(no3)
print(type(no3))

result

5 <class 'int'> get a value from user <class 'str'> 5.5 <class 'float'>

Variables :
Variable is a reserved memory location to store values.

for example :

address = " 3, Kosakulam, madurai"
(reference variable
or
identifiers)

= ----> is called Assignment operator

Rules for Python variables:

A variable name must start with a letter or the underscore character
A variable name cannot start with a number
A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )
Variable names are case-sensitive (age, Age and AGE are three different variables)
Do not use any of Python's reserved keywords (e.g., for, if, while, etc.) as variable names.

( 1.Name should be meaningful.
bike_no = 1234
2.Space is not allowed.
bike_no
bikeNo
3.Number are allowed but not in first place.
age1
4.No special character is allowed except _ and $ symbol )

return
The return statement is used to exit a function and send a value back to the caller.

for example

def add(no1, no2):
    print(no1+no2)
    return no1+no2


def subtract(no1,no2):
    print(no1-no2)
    return no1-no2

def multiply(no1,no2):
    print(no1*no2)

def divide(no1,no2):
    print(no1/no2)


result1 = add(100,50)
result2 = subtract(50,25)
multiply(result1,result2)

result
150
25
3750

pass :
The pass statement is used as a placeholder for future code.

example

def add(no1, no2):
    print(no1+no2)
    return no1+no2

def subtract(no1,no2):
    print(no1-no2)
    return no1-no2

def multiply(no1,no2):
    print(no1*no2)

def divide(no1,no2):
    pass


result1 = add(100,50)
result2 = subtract(50,25)
multiply(result1,result2)
divide(result1,result2)

result
150
25
3750

Day 2 in Python

varatharajan — Tue, 12 Nov 2024 18:46:52 +0000

Function :
A function is a block of code which only runs when it is called. You can pass data, known as parameters, into a function.

There are two types of function in python.
Built-in library function (pre-defined function)
User-defined function

*Built-in library function: *
There are Standard functions in Python that are available to use.

for Example :
input()
print()

input() function :
The input() function allows user input.
for example :
x = input("Enter your name : ")

print() function
The print() function prints the specified message to the screen, or other standard output device.
for example
print("welcome to our class")

User-defined function:
We can create our own functions based on our requirements.

We can define a function in Python, using the def keyword. We can add any type of functionalities and properties to it as we require.

for example

A = int(input("Enter your A value : "))
B = int(input("Enter your B value : "))
C = input("Enter your operator : ")

def calculate(A,B,C):
  if C == '+':
    print("Addition--->",A+B)
  if C == '-':
    print("subtraction---->",A-B)

calculate(A,B,C)

*Result *
Enter your A value10
Enter your B value20
Enter your operator+
Addition--->30
Enter your A value20
Enter your B value10
Enter your operator-
subtraction---->10