I would suggest using argparse https://docs.python.org/3/library/argparse.html as it handles all of that natively... including validating arguments, showing errors, help, etc... however, assuming you don't want to;
Send it to stdout, that allows the user to redirect it if they want to (and plays better with other dev-ops tools) Don't run it through a pager, the user can do that if needed... HOWEVER - If you have enough help that you need to page it, consider moving much of it to application documentation (either hosted, or as a doc / txt file). The command line help should simply be enough hints to remember what the various parameters are, not a full explanation about what it can do (unless the app is really simple). - Alternatively, you can have a multi-level help approach where the user can type "app_name argument /help" and get more detailed information about that specific argument. > -----Original Message----- > From: Python-list [mailto:python-list-bounces+d.strohl=f5....@python.org] > On Behalf Of alister > Sent: Thursday, April 28, 2016 9:45 AM > To: python-list@python.org > Subject: Re: What should Python apps do when asked to show help? > > On Fri, 29 Apr 2016 02:33:56 +1000, Steven D'Aprano wrote: > > > I have an application written in Python which accepts -h or --help to > > show help. I can: > > > > (1) print the help text to stdout; > > > > (2) run the help text through a pager; > > > > (3) do something else? > > > > > > Many command line tools simply output help to stdout (or stderr, if > > they're evil), which makes it easy to redirect the help to a file, > > pass it to grep, etc. For example: > > > > [steve@ando ~]$ wget --help | wc -l 136 > > > > Other tools automatically launch a pager, e.g. man. (Admittedly, man > > --help does not use a pager.) The Python help system, pydoc, does the > > same. > > > > I was thinking that my application could use pydoc: > > > > def do_help(): > > import pydoc pydoc.pager(HELPTEXT) > > > > or just print the help text: > > > > def do_help(): > > # Do I really need to show this??? > > print(HELPTEXT) > > > > > > but I was thinking of doing both: give my application a subcommand or > > an option to display help directly in a pager, while -h and --help > > print to stdout as normal. > > > > What do you think? Too clever? > > Send it to stdout, this gives the user the most choice. > > if there is enough that I want it paged then I will pipe it to a pager. > > do one job, do it well and don't reinvent the wheel unnecessarily. > > > > -- > Nobody shot me. > -- Frank Gusenberg, his last words, when asked by police > who had shot him 14 times with a machine gun in the Saint > Valentine's Day Massacre. > > Only Capone kills like that. > -- George "Bugs" Moran, on the Saint Valentine's Day > Massacre > > The only man who kills like that is Bugs Moran. > -- Al Capone, on the Saint Valentine's Day Massacre > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
