CLN: Exception in core.dtypes
I can't duplicate the black complaints on Mac or Linux, both with 19.3b0 lgtm. merge pending CI updates. Just a guess but is it the double quote escaping that black doesn't like? Seems like 4 files failed and that's done in 4 files. Maybe single quotes for the outer string 

I think black mostly tries to avoid backslash escaping:

https://github.com/psf/black#strings That seems to fix it, thanks @WillAyd  lgtm. @WillAyd if you had comments. Thanks @jbrockmendel 