[lelandbatey]

YAPF is slower than Black for many degenerate cases, a fact I notice most strongly since I use an "auto-format file on file save" extension in my editor. The case I found in particular was editing large JSON schema definitions in Python, as they're represented as deeply nested dictionaries. Black seems to format them in linear time based on the number of bytes in the file, while YAPF seems to get exponentially slower based on the complexity of the hard-coded data structure. It was a niche case, and the maximum slowdown was only ~1-2 seconds, but that editing freeze was quite annoying.