@dstansby theeval is just to prevent redundant definition of the string 'AutoDateLocator(maxticks=8)'and the locator itself, i.e. it's meant as a shortcut of writing e.g.

locators = [    ('AutoDateLocator(maxticks=8)', AutoDateLocator(maxticks=8), '2003-02-01', '%Y-%m'),    ...

Maybe usingeval is not really best practice but it reduces the possibility of mistakes/inconsistencies between the code and the text in this case.

I guess I but the argument that theeval is useful here...

Maybe usingeval is not really best practice but it reduces the possibility of mistakes/inconsistencies between the code and the text in this case.

Would a repr on the objects (assuming it exists) print anything different from the eval?

@story645repr(AutoDateLocator(maxticks=8)) gives'<matplotlib.dates.AutoDateLocator object at 0x000001CE4F687CA0>'.

Defining nicereprs wouldn't be enough, however, as we also need the arguments of the function calls.

Defining nice reprs wouldn't be enough, however, as we also need the arguments of the function calls.

Why couldn't those be in the repr?

@story645
I only have very basic knowledge of python in this respect, maybe I'm completely wrong:

When I tryAutoDateLocator.__repr__ = lambda self: f'AutodateLocator(maxticks={self.maxticks})' thenrepr(AutoDateLocator(maxticks=8)) returns'AutodateLocator(maxticks={0: 8, 1: 8, 3: 8, 4: 8, 5: 8, 6: 8, 7: 8})', i.e. the class variablemaxticks. I don't know how to get the value passed in during the function call. But even if this is possible, I find defining all therepr rather verbose and a bit hacky as compared to a simpleeval.

In an ideal world we would define sensible__repr__s on each of the locators/formatters so they could be used - I think that's a stretch goal, and this PR is worth considering regardless of that.

Thanks@StefRe for your very helpful contributions!

@jklymak Thanks!
What about therrulewrapper issue I mentioned at thevery beginning? Open a new issue for this? Should I (for the time being) remove the reference torrulewrapper as there's no link:

Sure, open an issue. Seems the solution is to add a docstring to rrulewrapper if it is public API...