Python 多条件输入验证：语法正确？

Question

我创建了一个简单的程序，提示用户猜测 1 到 20 之间的数字。最初，我的程序只是提示用户输入是太高还是太低。 后来我添加了一个 function，当用户的输入超出范围（低于 1 或高于 20）时会提示用户。 该程序运行良好，但是我想知道我的格式和语法是“正确”还是“正确”。

magic_number = 12

# get input from user 
user_number = int(input('What is the magic number between 1 and 20 ? '))

# attempting to create an efficient while loop
while True:
    if user_number < 12 and user_number >= 1:
        # error message 
        print('Your number is too low. Please try again.')
        # ask for input again
        user_number = int(input('What is the magic number between 1 and 20 ? '))
    elif user_number > 12 and user_number <= 20:
        # error message
        print('Your number is too high. Please try again.')
        # ask for input again
        user_number = int(input('What is the magic number between 1 and 20? '))
    elif user_number < 1 or user_number > 20:
        # error message
        print('Your number is out of range. Please try again.')
        # ask for input again
        user_number = int(input('What is the magic number between 1 and 20? '))
    elif user_number == magic_number:
        print('Congratulations! You have guessed the magic number.')
        break

Answer 1

如果您对格式化代码的官方“Pythonic”方式感兴趣，这就是 PEP8 规范的全部内容： https://www.python.org/dev/peps/pep-0008/ 。

查看您的代码，我有一些建议可以使事情变得更清洁和更易于维护：

1. 尽量避免在多个位置硬编码相同的常量值（例如 1、20、12）。 这样，如果您想稍后更改它们，您只需在一个地方进行更改。
2. 如果您可以帮助它（或将其移动到函数中），请尽量避免在多个地方重复逻辑，原因与 #1 相同。 如果你有一个错误，你只需要在一个地方修复它。

您可以做很多事情，但这里有一个示例，说明仅遵循这两条评论可能会是什么样子：

magic_number = 12

min_number = 1
max_number = 20

# attempting to create an efficient while loop
while True:
    # get input from user
    user_number = int(input('What is the magic number between {} and {} ? '.format(min_number, max_number)))

    if user_number < magic_number and user_number >= min_number:
        print('Your number is too low. Please try again.')
    elif user_number > magic_number and user_number <= max_number:
        print('Your number is too high. Please try again.')
    elif user_number < min_number or user_number > max_number:
        print('Your number is out of range. Please try again.')
    elif user_number == magic_number:
        print('Congratulations! You have guessed the magic number.')
        break

也许将来要尝试的一些事情可能是弄清楚如果用户不输入数字时如何处理，或者每次使用random模块生成不同的幻数而不是将其硬编码为 12。

祝你好运，希望能有所帮助。