问题

You caught an exception in an except block, but now you want to reraise it.

解决方案

Simply use the raise statement all by itself. For example:

>>> def example():
...     try:
...             int("N/A")
...     except ValueError:
...             print("Didn"t work")
...             raise
...


>>> example()
Didn"t work
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in example
ValueError: invalid literal for int() with base 10: "N/A"
>>>

讨论

This problem typically arises when you need to take some kind of action in response toan exception (e.g., logging, cleanup, etc.), but afterward, you simply want to propagatethe exception along. A very common use might be in catch-all exception handlers:

try:...except Exception as e:

Process exception information in some way...

Propagate the exceptionraise