How to Solve Python Integer Rounding Problems with Simple Functions

1. Introduction

Hello, I am a Python enthusiast. Recently a follower asked a basic Python rounding question in a chat group, which is illustrated in the screenshots below.

2. Implementation Process

The initial solution attempted to use a series of conditional returns:

def brf_cnt(consume_number):
    if abs(consume_number) < 13:
        return 1
    elif 13 <= abs(consume_number) < 21:
        return 2
    else:
        return consume_number // 10 + 1

if __name__ == '__main__':
    consume_number = 33
    print(brf_cnt(consume_number))

This works for many cases but fails when the input is 30 (expected 3, got 4). A corrected approach uses math.ceil to round up:

import math
cl = math.ceil
nums = [10, 13, 20, 21, 30, 31, 33]
for i in nums:
    if i < 13:
        print(1)
    else:
        print(cl(i/10))

Another contributor offered a similar solution, and a third version simplifies the logic with a ternary expression:

def money_people(x):
    return 1 if x < 13 else (x - 1) // 10 + 1

print(money_people(20))

All three implementations satisfy the problem requirements, as shown in the following screenshots:

3. Summary

This article presented a basic Python rounding problem, analyzed why the first attempt produced incorrect results, and provided three clean solutions—including a math.ceil method and a ternary operator version—helping readers quickly resolve similar issues.