protect_utf8(wrapped_function, encoding='UTF-8')

Temporarily convert a UTF-8 string to Unicode to prevent breakage.

protect_utf8 is a function decorator that can prevent naive functions from breaking UTF-8.

If the wrapped function takes a string, and that string happens to be valid UTF-8, convert it to a unicode object and call the wrapped function. If a conversion was done and if a unicode object was returned, convert it back to a UTF-8 string.

The wrapped function should take a string as its first parameter and it may return an object of the same type. Anything else is optional. For example:

def truncate(s):
    return s[:1]

Pass encoding if you want to protect something other than UTF-8.

Ideally, we'd have unicode objects everywhere, but sometimes life is not ideal. :)