Python difflib with regular expressions

Can I use regular expressions in difflib?

Specifically, I'd like to do:

difflib.context_diff(ac开发者_开发技巧tual, gold)

Where actual is:

[master 92a406f] file modified

and gold is:

\[master \w{7}\] file modified

It looks like you mean that you want to ignore the 92a406f part of the actual file. You should write a scrubber that uses regexes to scrub the parts you want to ignore:

actual = re.sub(r"\[master \w{7}\]", "[master *******]", actual)

then store the scrubbed gold file. Then you can use standard difflib to compare the scrubbed actual to the scrubbed gold.

If you really want to pursue a regex-based diff, then you can create your own string-like object that defines __eq__ based on regex matching, and use difflib on a sequence of those objects. I wouldn't recommend it, though.

What I just did is: replace the find_longest_match function of difflib with a copy, but replace the == invocations by invocation of a check that when things are not equal try to interpret the left side as regexp (and returns true on any error, e.g. when it is not a valid regexp).

I am using it for unit tests expected output matching and so far it is working really fine.