how can I specify a list on the command line
Solution 1:
Wrap the string in quotes to avoid [ being interpreted as a glob expression.
python -m apps.test_hydra 'data.data_files=[x,y]'
On a hydra github issue, they use the following syntax. You might have to do something similar.
$ python -m apps.test_hydra 'data@data_files=[x, y]'
Solution 2:
Use " \ " before special characters.
python -m apps.test_hydra data.data_files=\[x,y\]