Python Practice Programs

In this blog, I have practiced some important Python number-based programs. These programs helped me understand while loops, functions, conditional statements, digit extraction, mathematical operations, and problem-solving logic.

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1. Find Two Prime Numbers Whose Sum Is Target

This program tries to find two prime numbers whose sum is equal to the given target number.

Code

def find_prime(no):
    div = 2
    while div <= no//2:
        if no % div == 0:
            return False
        div += 1
    else:
        return True


prime1 = 2
target = 68

i = 1
while i <= target//2:

    result = find_prime(prime1+i)

    if result == True:
        prime2 = prime1+i

        if(prime1+prime2 == target):
            print(prime1, "+", prime2, "=", prime1+prime2)
            break
        else:
            prime1 = prime2
            i = 0

    i = i+1

Output

2 + 66 = 68

Note: The current logic has a mistake because 66 is not a prime number. A correct prime pair for 68 would be 7 + 61 = 68.

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2. Neon Number

A Neon Number is a number where the sum of the digits of its square is equal to the original number.

For example:

9² = 81
8 + 1 = 9

Therefore, 9 is a Neon Number.

Code

num = 9
copy = num

num = num * num
result = 0

while num > 0:
    digit = num % 10
    result += digit
    num //= 10

if result == copy:
    print(f"{copy} is neon number")
else:
    print(f"{copy} is not neon number")

Output

9 is neon number

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3. Strong Number

A Strong Number is a number where the sum of the factorial of each digit is equal to the original number.

For example:

145

1! + 4! + 5!
= 1 + 24 + 120
= 145

Therefore, 145 is a Strong Number.

Code

num = 145
copy = num
result = 0


def factorial(num):
    res = 1

    while num > 0:
        res = res * num
        num = num - 1

    return res


while num > 0:
    last = num % 10
    result += factorial(last)
    num //= 10


if copy == result:
    print(f"{copy} is Strong number")
else:
    print(f"{copy} is not Strong number")

Output

145 is Strong number

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4. Automorphic Number

An Automorphic Number is a number whose square ends with the original number.

For example:

25² = 625

The last two digits are 25, which is the original number.

Therefore, 25 is an Automorphic Number.

Code

num = 25
copy = num
digit = 0

while num > 0:
    digit += 1
    num = num // 10

n = copy
n = n * n
i = 1

while digit > 0:
    i = i * 10
    digit -= 1


if n % i == copy:
    print(f"{copy} is Automorphic Number")
else:
    print(f"{copy} is not Automorphic Number")

Output

25 is Automorphic Number

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5. Duck Number

A Duck Number is a number that contains at least one zero.

For example:

1024

Since 1024 contains 0, it is a Duck Number.

Code

num = 1024
copy = num
found = False

while num > 0:
    digit = num % 10

    if digit == 0:
        found = True

    num //= 10


if found:
    print(f"{copy} is Duck Number")
else:
    print(f"{copy} is not Duck Number")

Output

1024 is Duck Number

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6. Spy Number

A Spy Number is a number where the sum of its digits is equal to the product of its digits.

For example:

1124

Sum:
1 + 1 + 2 + 4 = 8

Product:
1 × 1 × 2 × 4 = 8

Since both are equal, 1124 is a Spy Number.

Code

num = 1124
copy = num
add = 0
product = 1

while num > 0:
    digit = num % 10

    add += digit
    product *= digit

    num = num // 10


if add == product:
    print(f"{copy} is Spy Number")
else:
    print(f"{copy} is Not Spy Number")

Output

1124 is Spy Number

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These number-based programs are a good way to strengthen Python fundamentals.

The main goal of these exercises is not just to get the output, but to understand how loops, conditions, functions, and mathematical operations work together to solve a problem.