python - 如何区分同一try语句中发生的不同异常

Question

例如:

try:
    myfruits = FruitFunction()    #Raises some exception (unknown)
    assert "orange" in myfruits   #Raises AssertionError (known)

except:
    # I don't know how to distinguish these two errors :(

我需要从所有其他未知的异常中过滤掉一种特定类型的异常(已知的)。我还需要断言来继续相同的异常处理，

try:
    myfruits = FruitFunction()    #Raises some exception (unknown)
    assert "orange" in myfruits   #Raises AssertionError (known)

except AssertionError:
    # Handle Assertion Errors here
    # But I want the except below to happen too!

except:
    # Handle everything here

我将添加一个真实的例子来更简洁地传达这个想法:

try:
    # This causes all sorts of errors
    myurl = urllib.urlopen(parametes)

    # But if everything went well
    assert myurl.status == 202

    # proceed normal stuff

except:
    # print "An error occured" if any error occured
    # but if it was an assertion error,
    # add "it was something serious too!"

Answer 1

try:
    try:
        myfruits = FruitFunction()    #Raises some exception (unknown)
        assert "orange" in myfruits   #Raises AssertionError (known)
    except AssertionError:
        # handle assertion
        raise
except Exception:
    # handle everything

我假设您不能将抛出不同异常的两个语句分开(例如，因为它们在另一个函数中一起关闭)。如果可以，那么以下内容会更准确、更直接:

try:
    myfruits = FruitFunction()    #Raises some exception (unknown)
    try:
        assert "orange" in myfruits   #Raises AssertionError (known)
    except AssertionError:
        # handle assertion
        raise
except Exception:
    # handle everything

它更精确，因为如果 FruitFunction() 引发未知异常恰好是 AssertionError那么它就不会被夹在内部try .如果不分离语句，就没有(明智的)方法来区分从两个不同地方抛出的两个相同类型的异常。所以对于第一个代码，你最好希望 FruitFunction()要么不提高AssertionError ，或者如果是，则可以像处理另一个一样处理它。