Python — Practical Programs 100+ Part 1

1. Program to Print Hello world in Python
2. Program to Find the Square Root of a Number
3. Program to Sum Two Numbers
4. Program to Swap Two Variables
   Without using third variable
   Swap Values using Arithmetic [*, /] Operators
   Swap Values using Simple Constructor — tuple Pack / Unpack
   Swap Values using Bitwise XOR operator
5. Program to Convert Celsius to Fahrenheit
6. Find ASCII Value of Character
7. Program to Calculate the Area of a Triangle
8. Program to Convert Kilometers to Miles
9. Program to Convert Decimal to Binary and Hexadecimal
10. Program to Solve Quadratic Equation
11. Program to Check if a Number is Odd or Even
12. Program to Check if a Number is Positive, Negative or Zero
13. Program to Find the Largest Among Three Numbers
14. Program to Check Leap Year
15. Program to Display the multiplication Table
16. Program to Check Prime Number
17. Program to Find the Factorial of a Number
18. Program to Print the Fibonacci sequence
19. A Program to Find the Sum of Natural Numbers
    using for loop
    using formula
20. Program to Find List of Numbers Divisible by 4
    Using Filter method
    Using for Loop
    List comprehension
21. Program to Make a Simple Calculator
22. Program to Check Whether a String is Palindrome or Not
23. Program to Check Armstrong Number
24. Print all Prime Numbers in a Range
25. Program to Find Armstrong Number in a Range

Program to Print Hello world in Python

# 1. A program to print Hello, world!  
print('Hello, World!')

Hello, World!

A Program to Find the Square Root of a Number

# 2. A Program to Find the Square Root of a Number

num = float(input('Enter a number: '))
sqrt = num**0.5
print('The square root of %0.2f is %0.2f'%(num,sqrt))

Enter a number: 100
The square root of 100.00 is 10.00

Program to Sum Two Numbers

# Program to add two numbers using + operator  
num1 = eval(input("enter number 1 "))
num2 = eval(input("enter number 2 "))
 # Sum the two numbers
result = num1 + num2
 # Display the result
print('The sum of {0} and {1} = {2}'.format(num1, num2, result))

enter number 1 12
enter number 2 21
The sum of 12 and 21 = 33

Program to Swap Two Variables

x = input('Enter x value: ')
y = input('Enter y value: ')
 # create a temporary variable and swap the values
temp = x
x = y
y = temp
print('The value of x after swapping: {}'.format(x))
print('The value of y after swapping: {}'.format(y))

Enter x value: 12
Enter y value: 21
The value of x after swapping: 21
The value of y after swapping: 12

— Without using third variable

x =int(input('Enter x value: '))
y =int(input('Enter y value: '))

# use of basic arithmetic [+ & -] operator
x = x+y;
y = x-y;
x = x-y;
print('The value of x after swapping: {}'.format(x))
print('The value of y after swapping: {}'.format(y))

Enter x value: 12
Enter y value: 21
The value of x after swapping: 21
The value of y after swapping: 12

— Swap Values using Arithmetic [*, /] Operators

x =int(input('Enter x value: '))
y =int(input('Enter y value: '))
 # use of basic arithmetic operators
x = x*y;
y = x/y;
x = x/y;
print('The value of x after swapping: {}'.format(x))
print('The value of y after swapping: {}'.format(y))

Enter x value: 12
Enter y value: 21
The value of x after swapping: 21.0
The value of y after swapping: 12.0

— Swap Values using Simple Constructor — tuple Pack / Unpack

x =input('Enter x value: ')
y =input('Enter y value: ')
 # apply simple constructor below
x,y=y,x
print('The value of x after swapping: {}'.format(x))
print('The value of y after swapping: {}'.format(y))

Enter x value: 12
Enter y value: 21
The value of x after swapping: 21
The value of y after swapping: 12

— Swap Values using Bitwise XOR operator

x =int(input('Enter x value: '))
y =int(input('Enter y value: '))
x =x^y
y =x^y
x =x^y
print('The value of x after swapping: {}'.format(x))
print('The value of y after swapping: {}'.format(y))

Enter x value: 12
Enter y value: 21
The value of x after swapping: 21
The value of y after swapping: 12

Program to Convert Celsius to Fahrenheit

celsius =float(input("Enter a value in Celsius: "))
 # calculate fahrenheit
fahrenheit =(celsius * 1.8) + 32
print('%0.1f° Celsius = %0.1f° Fahrenheit.'%(celsius,fahrenheit))

Enter a value in Celsius: 32
32.0° Celsius = 89.6° Fahrenheit.

Find ASCII Value of Character

cha=str(input('Enter any character: '))
print('ASCII value of {0} = {1}'.format(cha,ord(cha)))

Enter any character: A
ASCII value of A = 65

Program to Calculate the Area of a Triangle

Base =float(input('Enter the base value: '));
Height =float(input('Enter the height value: '));
Area = (Base * Height) / 2;
print('The area of the triangle is {} '.format(Area))

Enter the base value: 5
Enter the height value: 3
The area of the triangle is 7.5

— Calculate the area of triangle using sides of triangle

a =float(input('Enter first side: '))
b =float(input('Enter second side: '))
c =float(input('Enter third side: '))
s = (a + b + c) / 2
 # Calculate the area
Area =(s*(s-a)*(s-b)*(s-c))**0.5
print('The area of the triangle is %0.2f' %Area)

Enter first side: 2
Enter second side: 3
Enter third side: 4
The area of the triangle is 2.90

Program to Convert Kilometers to Miles

km =float(input("Enter km value: "))
 # conversion rate
rate =0.621371
miles =km*rate
print('%0.2f km is equal to %0.2f miles'%(km,miles))

Enter km value: 10
10.00 km is equal to 6.21 miles

Program to Convert Decimal to Binary and Hexadecimal

num_dec =int(input('Enter a number: '))
print('Binary equivalent of {0} = {1}'.format(num_dec,bin(num_dec)))
print('Hexadecimal equivalent of {0} = {1}'.format(num_dec,hex(num_dec)))

Enter a number: 10
Binary equivalent of 10 = 0b1010
Hexadecimal equivalent of 10 = 0xa

Program to Solve Quadratic Equation

import cmath
a = float(input('Enter a value: '))
b = float(input('Enter b value: '))
c = float(input('Enter c value: '))
 # calculate the discriminant
d = (b**2) - (4*a*c)
 # find two solutions
root1 = (-b-cmath.sqrt(d))/(2*a)
root2 = (-b+cmath.sqrt(d))/(2*a)
print('The solution is: {0} + {1}'.format(root1,root2))

Enter a value: 2
Enter b value: 2
Enter c value: 2
The solution is: (-0.5-0.8660254037844386j) + (-0.5+0.8660254037844386j)

Program to Check if a Number is Odd or Even

num = int(input('Enter any number: '))
if (num % 2) == 0:
   print('{0} is an Even Number'.format(num))
else:
   print('{0} is an Odd Number'.format(num))

Enter any number: 1
1 is an Odd Number

Program to Check if a Number is Positive, Negative or Zero

num =float(input('Enter any number: '))
if num > 0:
   print('This is a Positive number')
elif num == 0:
   print('This is Zero')
else:
   print('This is a Negative number')

Enter any number: -1
This is a Negative number

Program to Find the Largest Among Three Numbers

num1 =int(input('Enter first number: '))
num2 =int(input('Enter second number: '))
num3 =int(input('Enter third number: '))
if (num1 >= num2) and (num1 >= num3):
   bigNum = num1
elif (num2 >= num1) and (num2 >= num3):
   bigNum = num2
else:
   bigNum = num3
print('The largest number = {0}'.format(bigNum))

Enter first number: 3
Enter second number: 5
Enter third number: 1
The largest number = 5

Program to Check Leap Year

year =int(input('Enter a year: '))
if (year % 400) == 0:
           print('{0} is a leap year'.format(year))

elif year % 4==0 and year % 100 != 0 :
    print('{0} is a leap year'.format(year))
       
else:
    print('{0} is not a leap year'.format(year))

Enter a year: 2010
2010 is not a leap year

Program to Display the multiplication Table

num=int(input('Enter a number: '))
 # Iterate 10 times from i (ie 1 to 10)
for i in range(1, 11):
    print('{0} x {1} = {2}'.format(num,i,num*i))

Enter a number: 10
10 x 1 = 10
10 x 2 = 20
10 x 3 = 30
10 x 4 = 40
10 x 5 = 50
10 x 6 = 60
10 x 7 = 70
10 x 8 = 80
10 x 9 = 90
10 x 10 = 100

Program to Check Prime Number

num =int(input('Enter a number: '))
 # prime numbers must be greater than 1
if num>1:
   # check for factors
   for i in range(2,num):
       if (num % i) == 0:
           print('{0} is not a prime number'.format(num))
           break
   else:
       print('{0} is a prime number'.format(num))

Enter a number: 11
11 is a prime number

Program to Find the Factorial of a Number

num =int(input('Enter a number: '))
factorial=1
# check for negative, positive or zero
if num<0:
   print('Error! Negative nunber is not accepted')
elif num==0:
   print('Factorial of 0 = 1')
else:
   for i in range(1,num + 1):
       factorial = factorial*i
   print('Factorial of {0} = {1}'.format(num,factorial))

Enter a number: 3
Factorial of 3 = 6

Program to Print the Fibonacci sequence

nt_num = int(input('Enter nth term:  '))
 # first two terms
n1, n2 = 0, 1
count = 0
if nt_num <= 0:
   print('Enter only positive number')
elif nt_num == 1:
   print('Fibonacci sequence of {0} = {1}'.format(nt_num,n1))
else:
   print('Fibonacci sequence:')
   while count < nt_num:
       print(n1)
       nth = n1 + n2
       # update values
       n1 = n2
       n2 = nth
       count += 1

Enter nth term:  10
Fibonacci sequence:
0
1
1
2
3
5
8
13
21
34

Program to Find the Sum of Natural Numbers

num=int(input('Enter nth number: '))
if num < 0:
   print('Enter only positive number')
else:
   sum = 0
   while(num > 0):
       sum += num
       num -= 1
   print('Sum = {0}'.format(sum))

Enter nth number: 10
Sum = 55

— Sum of Natural Numbers Using n(n+1)/2

num =int(input('Enter nth number: '))
if num >= 0:
   sum = num*(num+1)/2
   print('Sum = {0}'.format(sum))
else:
    print('Enter only positive number')

Enter nth number: 10
Sum = 55.0

Program to Find List of Numbers Divisible by 4

— using filter method

nums = eval(input("Enter list of numbers in [] brackets "))
# using filter method 

result = list(filter(lambda x: (x % 4 == 0), nums))
print(result)

Enter list of numbers in [] brackets [1,2,3,4,5,6,7,8]
[4, 8]

— using for loop and if condition

# using for loop and if condition
nums = eval(input("Enter list of numbers in [] brackets "))

for i in nums:
    if i % 4 == 0:
        print(i, end= " " )

Enter list of numbers in [] brackets [1,2,3,4,5,6,7,8]
4 8

using list comprehension

nums = eval(input("Enter list of numbers in [] brackets "))

L1 = list(i for i in nums if i % 4 == 0 )
print(L1)

Enter list of numbers in [] brackets [1,2,3,4,5,6,7,8]
[4, 8]

Program to Make a Simple Calculator

# This function adds two numbers
def add(x, y):
    return x + y

# This function subtracts two numbers
def subtract(x, y):
    return x - y

# This function multiplies two numbers
def multiply(x, y):
    return x * y

# This function divides two numbers
def divide(x, y):
    return x / y

print("Select operation  ::   ")
print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")

while True:
    choice = input("Enter choice(1/2/3/4): ")
    if choice in ('1', '2', '3', '4'):
        try:
            num1 = float(input("Enter first number: "))
            num2 = float(input("Enter second number: "))
        except ValueError:
            print("Invalid input. Please enter a number.")
            continue

        if choice == '1':
            print(num1, "+", num2, "=", add(num1, num2))

        elif choice == '2':
            print(num1, "-", num2, "=", subtract(num1, num2))

        elif choice == '3':
            print(num1, "*", num2, "=", multiply(num1, num2))

        elif choice == '4':
            print(num1, "/", num2, "=", divide(num1, num2))
        next_calculation = input("Let's do next calculation? (yes/no): ")
        if next_calculation.lower() == "no":
          break
    else:
        print("Invalid Input")

Select operation  ::   
1.Add
2.Subtract
3.Multiply
4.Divide
Enter choice(1/2/3/4): 1
Enter first number: 1
Enter second number: 2
1.0 + 2.0 = 3.0
Let's do next calculation? (yes/no): no

Program to Check Whether a String is Palindrome or No

str1 =input('Enter a string: ')
str2 = str1[::-1]
if str1 == str2:
   print('The string is a palindrome.')
else:
   print('The string is not a palindrome.')

Enter a string: abc
The string is not a palindrome.

— using for Loop

# using for Loop 
str1 =input('Enter a string: ')
l1 = len(str1)
for i in range(len(str1)//2):
    if str1[i] != str1[l1 - i - 1]:
        print('The string is not a palindrome.')
        break
else:
    print('The string is a palindrome.')

Enter a string: aba
The string is a palindrome.

— using reversed function

str =input('Enter a string: ')  
str =str.casefold()
rev_str =reversed(str)
if list(str) == list(rev_str):
   print('The string is a palindrome.')
else:
   print('The string is not a palindrome.')

Program to Check Armstrong Number

num = int(input("Enter a number   "))
order = len(str(num))
sum = 0
temp = num
while temp > 0:
   digit = temp % 10
   sum += digit ** order
   temp //= 10
if num == sum:
   print('{0} is an Armstrong number'.format(num))
else:
   print('{0} is not an Armstrong number'.format(num))

Enter a number   371
371 is an Armstrong number

Print all Prime Numbers in a Range

min =int(input('Enter minimum range: '))
max =int(input('Enter maximum range: '))

if min > max :
    min , max = max, min

for num in range(min, max + 1):
   if num > 1:
       for i in range(2, num):
           if (num % i) == 0:
               break
       else:
           print(num, end= "  ")

Enter minimum range: 1
Enter maximum range: 20
2  3  5  7  11  13  17  19

Program to Find Armstrong Number in a Range

num_start =int(input('Enter start number: '))
num_end =int(input('Enter end number: '))
for num in range(num_start, num_end + 1):
    order = len(str(num))
    sum = 0
    temp = num
    while temp > 0:
        digit = temp % 10
        sum += digit ** order
        temp //= 10
    if num == sum:
        print(num)