Can I make decode(errors="ignore") the default for all strings in a Python 2.7 program?

Question

I have a Python 2.7 program that writes out data from various external applications. I continually get bitten by exceptions when I write to a file until I add .decode(errors="ignore") to the string being written out. (FWIW, opening the file as mode="wb" doesn't fix this.)

Is there a way to say "ignore encoding errors on all strings in this scope"?

Answer 1

As mentioned in my thread on the issue the hack from Sven Marnach is even possible without a new function:

import codecs
codecs.register_error("strict", codecs.ignore_errors)

Answer 2

You cannot redefine methods on built-in types, and you cannot change the default value of the errors parameter to str.decode(). There are other ways to achieve the desired behaviour, though.

The slightly nicer way: Define your own decode() function:

def decode(s, encoding="ascii", errors="ignore"):
    return s.decode(encoding=encoding, errors=errors)

Now, you will need to call decode(s) instead of s.decode(), but that's not too bad, isn't it?

The hack: You can't change the default value of the errors parameter, but you can overwrite what the handler for the default errors="strict" does:

import codecs
def strict_handler(exception):
    return u"", exception.end
codecs.register_error("strict", strict_handler)

This will essentially change the behaviour of errors="strict" to the standard "ignore" behaviour. Note that this will be a global change, affecting all modules you import.

I recommend neither of these two ways. The real solution is to get your encodings right. (I'm well aware that this isn't always possible.)