Error in openFeather(path) : Invalid: Not a feather file

When exporting the database to feather format, e.g. via

$ abc-export --db test.db --out test.feather --format feather --generation all

and importing in R via

> library('feather')
> data = read_feather('/tmp/test.feather')

we get

Error in openFeather(path) : Invalid: Not a feather file

this happens only for some versions, e.g. pyabc 0.10.3, pandas 1.0.4, R 3.6.3.

[nbungi]

Here is a work-around, as I encounter this issue even though I am using the latest arrow(2.0.0)/feather(0.3.5) packages in R. Using pyarrow(2.0.0) one can read and rewrite the feather file in “version 1”, which is then readable in R. import pyarrow.feather as feather feather_db = feather.read_feather('my_db.feather') feather.write_feather(feather_db, 'my_db_v1.feather', version=1)

[yannikschaelte]

The feather format appears to be somewhat cumbersome, with different tools implementing/supporting different versions etc… Not sure what lead to this error, but just to recapitulate a few options:

• As pointed out above by @nbungi , you can convert to version 1 post-hoc. Alternatively, you can also programmatically extract the database in https://github.com/ICB-DCM/pyABC/blob/main/pyabc/storage/export.py#L83 (this is the function called by abc-export) and then apply pandas.to_feather(filename, version=1).
• When importing in R, at least either feather::read_feather or arrow::read_feather can be used, with the latter in particular for version 1 exports.