added max_depth

[willmcgugan]

Work in progress.

Adds a max_depth parameter to fs.walk.

[coveralls]

Coverage increased (+0.0002%) to 99.951% when pulling e8bb2ea on walk-levels into 34824b2 on master.

[coveralls]

Coverage increased (+0.0002%) to 99.951% when pulling 02accb5 on walk-levels into 34824b2 on master.

[coveralls]

Coverage increased (+0.0002%) to 99.951% when pulling 02accb5 on walk-levels into 34824b2 on master.

[coveralls]

Coverage increased (+0.0002%) to 99.951% when pulling be36d32 on walk-levels into 34824b2 on master.

[willmcgugan]

Equivalent to https://docs.python.org/3/library/pathlib.html#pathlib.PurePath.parts

[coveralls]

Coverage increased (+0.0002%) to 99.951% when pulling 8decbf9 on walk-levels into 34824b2 on master.

[willmcgugan]

@althonos any thoughts?

[althonos]

Fine by me, kudos on the non-recursive implementation !

One remark though: the user may expect max_depths to work even if check_scan_dir is overriden, which will not be the case here.

A workaround would be:

class BaseWalker(object):

    def _check_scan_dir(self, fs, path, info, depth):
        return (self.max_depth is None or depth < self.max_depth) \
           and self.check_scan_dir(fs, path, info, depth)

    def check_scan_dir(self, fs, path, info, depth)
        """Override me !
        """
        return True

That way, check_scan_dir would be easier to override. (This may apply to the other check functions as well).

[coveralls]

Coverage increased (+0.0003%) to 99.951% when pulling 5a4a0c0 on walk-levels into 34824b2 on master.

[coveralls]

Coverage increased (+0.0003%) to 99.951% when pulling 323dace on walk-levels into 34824b2 on master.

[coveralls]

Coverage increased (+0.0003%) to 99.951% when pulling 323dace on walk-levels into 34824b2 on master.