python判断整除,如何检查一个数字是否可以被另一个数字整除（Python）？

I need to test whether each number from 1 to 1000 is a multiple of 3 or a multiple of 5. The way I thought I'd do this would be to divide the number by 3, and if the result is an integer then it would be a multiple of 3. Same with 5.

How do I test whether the number is an integer?

here is my current code:

n = 0

s = 0

while (n < 1001):

x = n/3

if isinstance(x, (int, long)):

print 'Multiple of 3!'

s = s + n

if False:

y = n/5

if isinstance(y, (int, long)):

s = s + n

print 'Number: '

print n

print 'Sum:'

print s

n = n + 1

解决方案

You do this using the modulus operator, %

n % k == 0

evaluates true if and only if n is an exact multiple of k. In elementary maths this is known as the remainder from a division.

In your current approach you perform a division and the result will be either

always an integer if you use integer division, or

always a float if you use floating point division.

It's just the wrong way to go about testing divisibility.