Python 3例外不打印新行

Question

I do not really know how to say it, but when I raise exception in python 3.2, '\\n' aren't parsed ...

Here is an example:

class ParserError(Exception):
    def __init__(self, message):
            super().__init__(self, message)

try:
    raise ParserError("This should have\na line break")
except ParserError as err:
    print(err)

It works like this:

$ ./test.py
(ParserError(...), 'This should have\na line break')

How do I make sure new lines are printed as new lines?

class ParserError(Exception):
    pass

or

print(err.args[1])

Answer 1

啊，err.message在2.6中被弃用 - 所以不再存在，所以...

print(err.args[1])

Answer 2

What's happening here is that the repr of your message string is being printed as part of passing the whole Exception object to print() , so the newline is being converted back into \\n . If you individually print the actual string, the actual newline will print.