python - 在 except 中引发异常而不调用原始异常

Question

我的代码如下:

try:
    *Do something*
except *anError*:
    if (condition):
        methodCalled()
    else:
        raise "my own Exception"

问题是，当我引发自己的异常(“我自己的异常”)时，也会引发“anError”异常。有没有办法确保当我引发自己的异常时，我捕获的错误不会引发？

Answer 1

引用docs :

When raising (or re-raising) an exception in an except or finally clause __context__ is automatically set to the last exception caught; if the new exception is not handled the traceback that is eventually displayed will include the originating exception(s) and the final exception.

这正是您的情况:

try:
    try:
        raise ValueError
    except ValueError:
        raise TypeError
except Exception as e:
    print('Original:', type(e.__context__)) # Original: <class 'ValueError'>
    print('Explicitly raised:', type(e))    # Explicitly raised: <class 'TypeError'>

只有一个事件异常；我可能写了 except TypeError 而不是 except Exception ，并且输出仍然是相同的。

如果要阻止 Python 打印原始异常，请使用 raise ... from None :

try:
    raise ValueError
except ValueError:
    raise TypeError from None