Re: What behavior would you expect?

From	Paul Rubin <no.email@nospam.invalid>
Newsgroups	comp.lang.python
Subject	Re: What behavior would you expect?
Date	2015-02-19 22:18 -0800
Organization	A noiseless patient Spider
Message-ID	<87r3tlds2l.fsf@jester.gateway.pace.com> (permalink)
References	(3 earlier) <mc5fiq$a3f$3@dont-email.me> <mailman.18902.1424376675.18130.python-list@python.org> <mc6emp$j1q$1@dont-email.me> <mailman.18908.1424409419.18130.python-list@python.org> <mc6hd4$j1q$2@dont-email.me>

Show all headers | View raw

Dan Sommers <dan@tombstonezero.net> writes:
> I'd still prefer an exception to None, and we agree on that an empty
> string is bad because it's not a non-string and it could be too easily
> mistaken for a filename.

Empty string would be bad.  Sometimes I like to simulate an option type,
by returning the value as a 1-element list if there's a value, otherwise
as an empty list.  So you could say

  filename = get_filename(...)[0]

if you want an exception in the failure case, or you could do something
like

  fs = get_filename(...)
  if len(fs) == 0:  ... # didn't get a filename

Thread

What behavior would you expect? Jason Friedman <jsf80238@gmail.com> - 2015-02-18 21:44 -0700
  Re: What behavior would you expect? Denis McMahon <denismfmcmahon@gmail.com> - 2015-02-19 14:16 +0000
    Re: What behavior would you expect? Chris Angelico <rosuav@gmail.com> - 2015-02-20 02:08 +1100
      Re: What behavior would you expect? Denis McMahon <denismfmcmahon@gmail.com> - 2015-02-19 20:03 +0000
        Re: What behavior would you expect? Chris Angelico <rosuav@gmail.com> - 2015-02-20 07:11 +1100
          Re: What behavior would you expect? Dan Sommers <dan@tombstonezero.net> - 2015-02-20 04:54 +0000
            Re: What behavior would you expect? Chris Angelico <rosuav@gmail.com> - 2015-02-20 16:16 +1100
              Re: What behavior would you expect? Dan Sommers <dan@tombstonezero.net> - 2015-02-20 05:40 +0000
                Re: What behavior would you expect? Jason Friedman <jsf80238@gmail.com> - 2015-02-19 22:49 -0700
                Re: What behavior would you expect? Paul Rubin <no.email@nospam.invalid> - 2015-02-19 22:18 -0800
                Re: What behavior would you expect? Chris Angelico <rosuav@gmail.com> - 2015-02-20 17:21 +1100
                Re: What behavior would you expect? Paul Rubin <no.email@nospam.invalid> - 2015-02-19 23:18 -0800

csiph-web