On Sun, Sep 18, 2016 at 3:26 AM, Steve D'Aprano
> help() does *not* return the same documentation as on the website. The
> website usually includes a lot more detail.
> The help() function introspects the python source code and formats the
> docstrings found, so it will often be very much smaller.
help() also uses a topics dict, from pydoc_data.topics, which gets
extracted when building the .rst docs. Check help('topics') and
help('keywords'). There's also help('symbols'), which lists the
punctuation symbols that help maps to various topics. For example,
help('**') gets mapped to help('POWER') and also prints a list of
related topics for the user, which includes "EXPRESSIONS" and
"OPERATORS" in this case.
Obviously modules in the standard library are documented in much more
detail in the python.org docs. pydoc_data would be gargantuan
otherwise. But I think there's actually enough info available in
help() that someone proficient in another language could use it to get
started programming in Python without any other documentation,
tutorials, or books.