DEPR: Positional arguments in to_* I/O methods

[lithomas1]

These should all be keyword only except for buf/path_or_buf argument (the first one).

• to_csv
• to_orc
• to_parquet
• to_pickle
• to_hdf
• to_sql
• to_dict
• to_excel
• to_json
• to_html
• to_feather
• to_latex
• to_stata
• to_gbq
• to_string
• to_clipboard
• to_markdown

cc @MarcoGorelli since you championed the last effort

[rmhowe425]

take

[lithomas1]

Going to mark this as a good first issue.

See #41485 as a starting point for how to do this.

You are basically doing the same, but for the to_* methods, and the only keyword that should be allowed to be positional (and not keyword only) is the first one specifying the buffer/file to write to.

(Please add your whatsnew to v2.2.0.rst for now.

In the future, if this issue is still open after 2.2.0 comes out, pick the whatsnew corresponding to the newest release that ends in a zero. e.g. v2.3.0.rst, ...)

If you need any help, please ask on Slack (#newcomers channel) to avoid cluttering up this issue, but if you'd like to take one of the methods, just comment which one you want below.

[rsm-23]

I'll take to_pickle

[rsm-23]

Taking to_string

[rsm-23]

taking to_latex and to_stata and to_markdown