9 Basic Python Programs You Can’t Miss

a = int(input('Enter first number: '))
b = int(input('Enter second number: '))
c = int(input('Enter code (1: add, 2: sub, 3: mul, 4: div, 5: mod): '))
r = 0

if c == 1:
    r = a + b
elif c == 2:
    r = a - b
elif c == 3:
    r = a * b
elif c == 4:
    r = a / b
elif c == 5:
    r = a % b
else:
    print('Invalid input')

print('Answer is', r)

Output:
Enter first number: 
1
Enter second number: 
2
Enter code (1: add, 2: sub, 3: mul, 4: div, 5: mod): 
1
Answer is 3

# Initialize a variable to store the sum
total_sum = 0

# Loop through numbers from 1 to 50
for i in range(1, 51):
    print(i)
    total_sum += i  # Add the current number to the sum

# Print the total sum
print("The sum of numbers from 1 to 50 is:", total_sum)

Output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
The sum of numbers from 1 to 50 is: 1275

for i in range(1, 101):
    print(i, end=' ')
    if i % 10 == 0:
        print()
        
Output:

1 2 3 4 5 6 7 8 9 10 
11 12 13 14 15 16 17 18 19 20 
21 22 23 24 25 26 27 28 29 30 
31 32 33 34 35 36 37 38 39 40 
41 42 43 44 45 46 47 48 49 50 
51 52 53 54 55 56 57 58 59 60 
61 62 63 64 65 66 67 68 69 70 
71 72 73 74 75 76 77 78 79 80 
81 82 83 84 85 86 87 88 89 90 
91 92 93 94 95 96 97 98 99 100

width = 5  # Specify the width of the rectangle
height = 4  # Specify the height of the rectangle

for i in range(height):
    for j in range(width):
        print("*", end=" ")
    print()  # Move to the next line after each row
    
Output:

* * * * * 
* * * * * 
* * * * * 
* * * * * 

height = 5  # Specify the height (number of rows) of the triangle

for i in range(1, height + 1):
    for j in range(i):
        print("*", end=" ")
    print()
    
Output:

* 
* * 
* * * 
* * * * 
* * * * * 

height = 5  # Specify the height (number of rows) of the triangle

for i in range(height, 0, -1):
    for j in range(i):
        print("*", end=" ")
    print()
    
Output:

* * * * * 
* * * * 
* * * 
* * 
*

n = int(input("Enter the number of terms in the Fibonacci series: "))

# Initialize the first two terms of the series
a, b = 0, 1

# Check if the number of terms is valid
if n <= 0:
    print("Please enter a positive integer.")
elif n == 1:
    print("Fibonacci Series:")
    print(a)
else:
    print("Fibonacci Series:")
    print(a)
    print(b)

    for _ in range(2, n):
        # Calculate the next term
        next_term = a + b

        # Print the next term
        print(next_term)

        # Update a and b for the next iteration
        a, b = b, next_term
        
Output:

Enter the number of terms in the Fibonacci series: 
15
Fibonacci Series:
0 1 1 2 3 5 8 13 21 34 55 89 144 233 377

num_str = input("Enter a number: ")

# Check if the input is a single character and a digit
if len(num_str) == 1 and num_str.isdigit():
    num = int(num_str)
    
    # Check if it's an even number
    if num % 2 == 0:
        print("The entered number is a single-digit even number.")
    else:
        print("The entered number is not an even number.")
else:
    print("Please enter a single-digit number.")
    
Output:

Enter a number: 
2
The entered number is a single-digit even number.


Enter a number: 
3
The entered number is not an even number.

# Using a for loop
for letter in range(ord('a'), ord('z') + 1):
    print(chr(letter), end=' ')
    
Output:
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