Day 3 of 100 Days of Python

 

Today is June 22nd, the third day of the 100 Days of Python Coding challenge. I am doing some Number Manipulation questions in Python that use a while loop and digit extraction.The first program checks for an Armstrong Number. To solve it, I use a while loop and a counter variable to get the number of digits in the input number. Then, with another loop, I use the while loop again, but this time extract a digit, raise it to the power of its number of digits and then add their sum in a separate variable 's'.```python

# Armstrong Number. An Armstrong number (like 153 or 371) is a number equal to the sum of its own digits raised to the power of the number of digits

n = int(input("Enter a number to check for Armstrong Number"))

p = n

s=0

c = 0

while n>0:

    c=c+1

    n = n//10

n = p

while n>0:

    d = n%10

    print(f"Current digit: {d}")

    s = d**c + s

    print(f"Current sum: {s}")

    n = n//10

print(f"No. of digits: {c}")

print(f"Sum of digit raised to number of digit: {s}")

if s==p:

    print("It is Armstrong Number")

else:

    print("It is not")

```I learned that in Python, instead of Math.pow, we use double asterisk (**) to raise a number to a power. I also discovered another method for calculating the number of digits in an input number. It is that we can use this syntax, `len(str(num))` which converts the number into a string and calculates its length.

The second program is to check whether a number is Prime number or not. Like all the other previous programs, this one was also very easy. Interestingly, while solving this program, I got to know a little trick.If I use break in for loop after a if statement  and just after that if I put an else, then if the loop runs completely,  meaning if the break statement does not get the control out of the loop block, then the statement under else will be executed, as showin in the console output.```python

n = int(input("Enter a number to check for prime number "))

for i in range(2, n):

    if n%i==0:

        print(f"{n} is divisible by {i}")

        break

else:

    print(f"{n} is prime number"

```