[Python-ideas] PEP for executing a module in a package containing relative imports

Jim Jewett jimjjewett at gmail.com
Sun Apr 22 19:11:52 CEST 2007

On 4/21/07, Brett Cannon <brett at python.org> wrote:
> On 4/21/07, Josiah Carlson <jcarlson at uci.edu> wrote:

> > After reading other posts in the thread, I'm going to put my support
> > into the sys.main variant.  It has all of the benefits of the builtin __name__
> > == __main__, with none of the drawbacks (no builtin!), and only a slight
> > annoyance of 'import sys', which is more or less free.

> Yeah, I am starting to like it as well.  Steven and Jim, what do you think?

Better than adding a builtin.

I'm not sure I like the idea of another semi-random object in sys
either, though.

(1)  One of the motivations was importing.  It looks like __file__
already has sufficient information.  I understand that relying on it
(or on __package__?) seems a bit hacky, but is it really worse than
adding something?

(2)  Is there a reason the main module can't appear in sys.modules
twice, once under the alias "__main__"?

# Equivalent to today
if __name__ == sys.modules["__main__"].__name__:

# Better than today
if __name__ is sys.modules["__main__"].__name__:

# What I would like (pending PEP I hope to write tonight)
if __this_module__ is sys.modules["__main__"]:


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