在Python中使用regex检查章节编号？

import re

def check_chapter_number(chapter_number):
    pattern = r'^\d+\.\d+$'  # 正则表达式模式，匹配数字.数字的格式
    if re.match(pattern, chapter_number):
        return True
    else:
        return False

# 测试示例
chapter_number1 = '1.1'
chapter_number2 = '2.3.4'
chapter_number3 = '3'
chapter_number4 = '4.5.6.7'

print(check_chapter_number(chapter_number1))  # 输出：True
print(check_chapter_number(chapter_number2))  # 输出：False
print(check_chapter_number(chapter_number3))  # 输出：False
print(check_chapter_number(chapter_number4))  # 输出：False