Abstract
This PEP describes a command-line driven online help facility for
Python. The facility should be able to build on existing
documentation facilities such as the Python documentation and
docstrings. It should also be extensible for new types and
modules.
Interactive use:
Simply typing "help" describes the help function (through repr()
overloading).
"help" can also be used as a function:
The function takes the following forms of input:
help( "string" ) -- built-in topic or global
help( <ob> ) -- docstring from object or type
help( "doc:filename" ) -- filename from Python documentation
If you ask for a global, it can be a fully-qualified name such as
help("xml.dom").
You can also use the facility from a command-line
python --help if
In either situation, the output does paging similar to the "more"
command.
Implementation
The help function is implemented in an onlinehelp module which is
demand-loaded.
There should be options for fetching help information from
environments other than the command line through the onlinehelp
module:
onlinehelp.gethelp(object_or_string) -> string
It should also be possible to override the help display function
by assigning to onlinehelp.displayhelp(object_or_string).
The module should be able to extract module information from
either the HTML or LaTeX versions of the Python documentation.
Links should be accommodated in a "lynx-like" manner.
Over time, it should also be able to recognize when docstrings are
in "special" syntaxes like structured text, HTML and LaTeX and
decode them appropriately.
A prototype implementation is available with the Python source
distribution as nondist/sandbox/doctools/onlinehelp.py.
Built-in Topics
help( "intro" ) - What is Python? Read this first!
help( "keywords" ) - What are the keywords?
help( "syntax" ) - What is the overall syntax?
help( "operators" ) - What operators are available?
help( "builtins" ) - What functions, types, etc. are built-in?
help( "modules" ) - What modules are in the standard library?
help( "copyright" ) - Who owns Python?
help( "moreinfo" ) - Where is there more information?
help( "changes" ) - What changed in Python 2.0?
help( "extensions" ) - What extensions are installed?
help( "faq" ) - What questions are frequently asked?
help( "ack" ) - Who has done work on Python lately?
Security Issues
This module will attempt to import modules with the same names as
requested topics. Don't use the modules if you are not confident
that everything in your PYTHONPATH is from a trusted source.