如何将 Nonetype 转换为 int 或 string? [英] How to convert Nonetype to int or string?

问题描述

我有一个 Nonetype 值 x，它通常是一个数字，但也可以是 None.我想除以一个数字，但 Python 提出:

I've got an Nonetype value x, it's generally a number, but could be None. I want to divide it by a number, but Python raises:

TypeError: int() argument must be a string or a number, not 'NoneType'

我该如何解决这个问题?

How can I solve this?

推荐答案

在其中一条评论中，您说:

In one of the comments, you say:

不知何故我得到了一个 Nonetype 值，它应该是一个 int，但它现在是一个 Nonetype 对象

Somehow I got an Nonetype value, it supposed to be an int, but it's now a Nonetype object

如果是您的代码，请弄清楚当您期望一个数字时如何获得 None 并阻止这种情况发生.

If it's your code, figure out how you're getting None when you expect a number and stop that from happening.

如果是别人的代码，找出它给出 None 的条件，并确定一个合理的值，使用通常的条件代码:

If it's someone else's code, find out the conditions under which it gives None and determine a sensible value to use for that, with the usual conditional code:

result = could_return_none(x)

if result is None:
    result = DEFAULT_VALUE

...甚至...

if x == THING_THAT_RESULTS_IN_NONE:
    result = DEFAULT_VALUE
else:
    result = could_return_none(x) # But it won't return None, because we've restricted the domain.

没有理由在这里自动使用 0 — 依赖于 None 的假"性的解决方案假设您会想要这个.DEFAULT_VALUE(如果它存在)完全取决于您的代码的用途.

There's no reason to automatically use 0 here — solutions that depend on the "false"-ness of None assume you will want this. The DEFAULT_VALUE (if it even exists) completely depends on your code's purpose.

这篇关于如何将 Nonetype 转换为 int 或 string?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！