raise和raise from捕获异常

参考：Python 中 raise 和 raise/from 的区别_python raise from_团子大圆帅的博客-CSDN博客

raise 与 raise ... from 的区别 - 知乎 (zhihu.com)

Python | raise...from... 是个什么操作？_小詹学 Python的博客-CSDN博客

 

raise/from 捕获：打印异常上下文消息，指出新异常是由旧异常引起的，这样的异常之间的关联有助于后续对异常的分析和排查。（更规范）

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>>> try: ...     a=2/0 ... except Exception as e: ...     raise Exception('分母不能为0') from  e ... Traceback (most recent call last):   File "<stdin>", line 2, in <module> ZeroDivisionError: division by zero   The above exception was the direct cause of the following exception:   Traceback (most recent call last):   File "<stdin>", line 4, in <module> Exception: 分母不能为0 >>>

 

raise from None：禁止/关闭自动显示异常上下文。

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>>> try: ...     a=2/0 ... except Exception as e: ...     raise Exception('分母不能为0') from  None ... Traceback (most recent call last):   File "<stdin>", line 4, in <module> Exception: 分母不能为0 >>>

 

raise自定义异常中捕获：可同时抛出自定义异常和原生异常，但是无法体现异常的关联

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>>> try: ...     a=2/0                               ... except Exception as e:                  ...     raise Exception(f'分母不能为0，{e}') ... Traceback (most recent call last):                                   File "<stdin>", line 2, in <module>                              ZeroDivisionError: division by zero                                                                                                     During handling of the above exception, another exception occurred:                                                                      Traceback (most recent call last):                                   File "<stdin>", line 4, in <module>                              Exception: 分母不能为0，division by zero                           >>>

　　

只raise抛出原生异常：只抛出原生异常

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>>> try: ...     a=2/0 ... except Exception as e: ...     raise e ... Traceback (most recent call last):   File "<stdin>", line 4, in <module>   File "<stdin>", line 2, in <module> ZeroDivisionError: division by zero >>>

　

只raise自定义异常：可同时抛出自定义异常和原生异常，但是无法体现异常的关联

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>>> try: ...     a=2/0 ... except Exception as e: ...     raise Exception('分母不能为0') ... Traceback (most recent call last):   File "<stdin>", line 2, in <module> ZeroDivisionError: division by zero   During handling of the above exception, another exception occurred:   Traceback (most recent call last):   File "<stdin>", line 4, in <module> Exception: 分母不能为0 >>>