FizzBuzz program in Python

FizzBuzz is a classic interview warm-up. Count from 1 upwards. For multiples of 3 print Fizz, for multiples of 5 print Buzz, for multiples of both print FizzBuzz, and for every other number print the number.

The program

for i in range(1, 16):
    if i % 15 == 0:
        print("FizzBuzz")
    elif i % 3 == 0:
        print("Fizz")
    elif i % 5 == 0:
        print("Buzz")
    else:
        print(i)

1
2
Fizz
4
Buzz
Fizz
7
8
Fizz
Buzz
11
Fizz
13
14
FizzBuzz

How it works

• i % 3 == 0 is true when i divides by 3 with no remainder.
• A number divisible by both 3 and 5 is divisible by 15, so i % 15 == 0 checks "both" in one test.
• The order of the checks matters. if/elif stops at the first true condition. If the % 3 check came first, 15 would print Fizz and never reach the FizzBuzz line.
• range(1, 16) gives 1 to 15. The end number is not included. Change it to range(1, 101) for the usual 1 to 100.

Another way: build the word

This version adds Fizz and Buzz to a string, so it needs no separate check for 15. It is also easier to extend: a third rule (here, Bazz for multiples of 7) is one more line.

for i in range(1, 22):
    word = ""
    if i % 3 == 0:
        word += "Fizz"
    if i % 5 == 0:
        word += "Buzz"
    if i % 7 == 0:
        word += "Bazz"
    print(word or i)

1
2
Fizz
4
Buzz
Fizz
Bazz
8
Fizz
Buzz
11
Fizz
13
Bazz
FizzBuzz
16
17
Fizz
19
Buzz
FizzBazz

word or i gives word if it is not empty, and i otherwise. An empty string counts as false in Python.