Reputation: 21

For loop execution in Python

I am new to python and just in the initial phase of the basics. Can someone please explain me how the for loop in the below code works? and I really don't get how number 9 is getting 3 as inner value.

Kindly tell me how the loops executes. TIA.

CODE:

for outer in range(2,10):
    for inner in range(2,outer):
        if not outer%inner:
            print(outer,'=',inner,'*',int(outer/inner))
            break   
    else:
        print(outer,'is prime')

Output:
2 is prime
3 is prime
4 = 2 * 2
5 is prime
6 = 2 * 3
7 is prime
8 = 2 * 4
9 = 3 * 3

Upvotes: 1

Answers (3)

Libra

Reputation: 2595

I commented your code below, It should explain what is going on.

# This loop loops through numbers 2-9, and assigns them to the variable 'outer'
for outer in range(2,10):
    # This loop loops through numbers 2-(outer-1), and assigns them to the variable 'inner'
    for inner in range(2,outer):
        # if outer % inner == 0, the code is executed
        if not outer%inner:
            # When this is executed for 9, it will print 9 = 3 * 3
            print(outer,'=',inner,'*',int(outer/inner))
            break   
    else:
        print(outer,'is prime')

Upvotes: 1