I expect it simply uses sphinx and I don't know if sphinx's search is easily customisable but the experience is really terrible when looking for the doc of a specific thing, *especially* when that thing is or is related to a builtin, which I'd expect to be extremely common. Though I expect part of the issue might also be that builtin or ABC methods are not documented *as such*, they're just written as code in tables.

For instance if you search "append": https://docs.python.org/3/search.html?q=append

On my end, neither list nor MutableSequence appear anywhere on this page, even scrolling down.

Searching for "list": https://docs.python.org/3/search.html?q=list

The documentation for the builtin "list" object also doesn't appear on the page. "Data Structures"[0] and "built-in types"[1] appear below the fold and the former is genuinely useful but also very easy to miss (I had not actually noticed it before going back in order to get the various links and try to extensively describe the issue). Neither actually links to the `list` builtin type though.

Above the fold we find various "list" methods and classes from the stdlib as well as the PDB `list` comment, none of which seems like the best match for the query.

And even Google doesn't help much there, most of the hits are for third-party documentation, and the one docs.python.org link is to the Data Structures page *of Python 2.7*.

[0] https://docs.python.org/3/tutorial/datastructures.html?highlight=list
[1] https://docs.python.org/3/library/stdtypes.html?highlight=list

Can we add search box using DuckDuckGo?
https://duckduckgo.com/?q=site%3Adocs.python.org%2F3%2F+list+append

Apparently it's at least a possibility on DDG's side (https://duckduckgo.com/search_box), don't know how easy it'd be to integrate in sphinx, or whether a hard dependency on an external search engine is acceptable / desirable.