EX.Midnight time doesn't exist

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暮晨 2018-11-16 23:46:30 +08:00 committed by 暮晨
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@ -39,7 +39,7 @@ So, here we go...
- [> Backslashes at the end of string/字符串末尾的反斜杠](#-backslashes-at-the-end-of-string字符串末尾的反斜杠)
- [> not knot!/别纠结!](#-not-knot别纠结)
- [> Half triple-quoted strings/三个引号](#-half-triple-quoted-strings三个引号)
- [> Midnight time doesn't exist?](#-midnight-time-doesnt-exist)
- [> Midnight time doesn't exist?/不存在的午夜?](#-midnight-time-doesnt-exist不存在的午夜)
- [> What's wrong with booleans?](#-whats-wrong-with-booleans)
- [> Class attributes and instance attributes](#-class-attributes-and-instance-attributes)
- [> yielding None](#-yielding-none)
@ -732,7 +732,7 @@ wtfpython
---
### > Midnight time doesn't exist?
### > Midnight time doesn't exist?/不存在的午夜?
```py
from datetime import datetime
@ -754,11 +754,12 @@ if noon_time:
```sh
('Time at noon is', datetime.time(12, 0))
```
The midnight time is not printed.
#### 💡 Explanation:
midnight_time 并没有被输出.
Before Python 3.5, the boolean value for `datetime.time` object was considered to be `False` if it represented midnight in UTC. It is error-prone when using the `if obj:` syntax to check if the `obj` is null or some equivalent of "empty."
#### 💡 说明:
在Python 3.5之前, 如果 `datetime.time` 对象存储的UTC的午夜时间(译: 就是 `00:00`), 那么它的布尔值会被认为是 `False`. 当使用 `if obj:` 语句来检查 `obj` 是否为 `null` 或者某些“空”值的时候, 很容易出错.
---