[IMPROVEMENT] Support pathlib Path

[obust]

Feature Request

All functions and methods taking a path as argument should support the pathlib Path type.
pathlib is the preferred API to handle paths in python 2.7+ (although there is no official PEP8 recommendation). It would be good to at support it and maybe even advertise it in the tutorials to display modern python usage.

The following functions fail when given a Path argument:

• autotvm.callback.log_to_file(filepath)
• autotvm.apply_history_best(filepath)
• lib.export_library(filepath)
• more ?

[tqchen]

Thanks, @obust for the suggestion. Given that pathlib is not available in 2.7, we might need to be a bit mindful on backward compatibility, other than that, I to tag this as help wanted and anyone is welcomed to bring in this feature

[obust]

Oh, you are right, it is not in the 2.7 standard library but is available through PyPI.
I guess there are two ways to go about it:

• cast path arguments to string in case they are Path
• use pathlib2 internally and cast path arguments to Path in case they are string https://www.scivision.co/python-idiomatic-pathlib-use/

[tqchen]

I think cast arguments to string is going to be easier for now

[tqchen]

@obust would you like to act on this?

[obust]

I don't have authorization to contribute PRs yet. Feel free to pick it up for now :)

[cchung100m]

Hi @tqchen

Do we still need to cast the variable filepath to string type in following three class?

• autotvm.callback.log_to_file(filepath)
• autotvm.apply_history_best(filepath)
• lib.export_library(filepath)

[tqchen]

@cchung100m feel free to take over and send a PR

[tqchen]

#3968