tab separator not recognized

[verajosemanuel]

I use it inside a Docker container (datasette) but seems that tab separated files (tsv) are not properly processed.
All columns are reduced to one.

csvs-to-sqlite my-file.tsv my-file.db -s $'\t'

/usr/local/lib/python3.7/site-packages/csvs_to_sqlite/utils.py:46: ParserWarning: Falling back to the 'python' engine because the 'c' engine does not support regex separators (separators > 1 char and different from '\s+' are interpreted as regex); you can avoid this warning by specifying engine='python'.
  dtype=dtype,
/usr/local/lib/python3.7/site-packages/pandas/core/generic.py:2789: UserWarning: The spaces in these column names will not be changed. In pandas versions < 0.14, spaces were converted to underscores.
  method=method,