OSError for dir_archive for many-variable inputs

[mmckerns]

The defaults for a dir_archive where the input is a long array can fail because the file name is too long.

Traceback (most recent call last):
  File "/Users/mmckerns/lib/python3.8/site-packages/klepto/_archives.py", line 582, in _lookup
    with open(_file, mode) as f:
OSError: [Errno 63] File name too long: '/Users/mmckerns/testing/truth/K_(3.141592653589793, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586, 6.283185307179586)/output.pkl'

What can be done here? Is there a better default or should the mitigation plan be documentation?

[mmckerns]

The easy thing to do is to use a file_archive... or to use a keymap to produce a short unique id (UID). The UID to input mapping could potentially be stored as part of the archive (essentially converting from {key:value} to {uid: (key, value)} for dir_archives... potentially would also resolve issues on preserving the historical order of the entries.

[mmckerns]

...or impose a rounding constraint on the indices for which you can round decimal places.