Yep. This is why I wrote Hypothesis: http://hypothesis.readthedocs.org/ / https://pypi.python.org/pypi/hypothesis

It's a lot more fully featured than the alternatives. It still lacks a few features of quickcheck (coarbitrary for function generation, labelling of examples), but it does example minimization and a whole bunch of things even quickcheck doesn't.

Hypothesis looks fantastic. A friend of mine and me spent a while on Google collecting Python QC implementations but didn't find any that implemented shrinking.

Hypothesis escaped our search. I don't know how but the project could do with better Google ranking :)

It has some really useful features like storing the counterexamples.

The CLA is a bit odd but I'm sure you have good reasons!

Yeah, the google ranking of Hypothesis when you search for python quickcheck is a thing that's been bugging me. There's a blog post from 2013 about it on the front page but none of the various places the project exists appear. I'm not sure what to do about it. I'm planning to do a bunch of shopping around and promoting of the library when the 1.0 release happpens (probably next week), so hopefully that should help.

The CLA is for a mix of weird personal reasons around open source and cynically practical ones. Hypothesis is 100% always going to remain free, but I'm trying to figure out ways that I can make money out of working on it (I've put a ton of work into it, so it would be a shame not to) and that's a lot easier if I retain the copyright. I may decide it's not useful and drop it later, but it's a lot easier to have it now and drop it later than it is to try and retroactively get one if it turns out I need it.

Realised I should have linked to http://hypothesis.readthedocs.org/en/master/internals.html to back up that "a whole bunch of things even quickcheck doesn't" claim. :-)

Thank you for bringing it in: I've been looking for a pure Python analogue of QuickCheck.