Question

In handout, Lecture 5, when defining the divisors there is some code in which I do not understand it's function.
It is the percent sign (%) after the x. How does that work? Here is the code :

x = 100

divisors = ()

for i in range(1,x):

if x%i == 0:
divisors = divisors+(i,)
print divisors

Answer 1

The % is the modulus operator, which gets the remainder of division.
For example 7 divided by 2 is 3 with a remainder of 1. Thus 7 % 2 = 1.

When a number perfectly divides a number, then it will have a remainder of 0. For example 4 / 2 = 2 remainder 0. You can use the % to determine factors or divisors of a number.

Answer 2

From i = 1 to 100, 100 will be divided by i, the remainder is x%i will equal zero if and only if the division is clean.

Suffice to say, this function finds all dividers for "100".

Matlab output for 100%i == 0:
1
2
4
5
10
20
25
50
100