如何在Python中使用冗余代码更好地编写多个异常?

问题描述：

如何更好地用Python编写以下代码段:

How can I better write the following snippet in Python:

try:
    statement-1
except Exception1:
    codeblock-1
    codeblock-2
except Exception2:
    codeblock-2

请明确一点，我想在第一个异常发生时执行两个代码块，而在第二个异常发生时仅执行这两个代码块中的后者.

Just to be clear, I want to execute two codeblocks when the first exception occurs, while only the latter of these two codeblocks when the second exception occurs.

答

如我所见，您有两个选择；要么:

You have two options, as I see it; either:

将codeblock-2提取到函数中，然后调用它(您只重复一行).或
在同一个except中捕获这两个异常，然后通过检查捕获的异常的类型来适当地处理这两种情况.

Extract codeblock-2 into a function and just call it (you repeat only one line this way); or
Catch both exceptions in the same except, then handle the two cases appropriately by checking the type of the caught exception.

请注意，这些方法并不互相排斥，如果与第一种方法结合使用，则第二种方法可能更具可读性.后者的片段:

Note that these aren't mutually exclusive, and the second approach is probably more readable if combined with the first. A snippet of the latter:

try:
    statement-1
except (Exception1, Exception2) as exc:
    if isinstance(exc, Exception1):
        codeblock-1
    codeblock-2

实际情况:

>>> def test(x, y):
    try:
        return x / y
    except (TypeError, ZeroDivisionError) as exc:
        if isinstance(exc, TypeError):
            print "We got a type error"
        print "We got a type or zero division error"


>>> test(1, 2.)
0.5
>>> test(1, 'foo')
We got a type error
We got a type or zero division error
>>> test(1, 0)
We got a type or zero division error

如何在Python中使用冗余代码更好地编写多个异常?

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