How to tell if I'm being run from a shell or a module

[dg.google.groups@thesamovar.net]

Hi all,

Is there any standard way to tell if the user is running from a module
or from an interactive shell like IDLE or IPython? The best I've come
up with so far is for a function to look at
getouterframes( currentframe())[1][1] (the filename in the frame record
of the frame that called the function), and check if it exists or not
with os.path.exists. IPython gives '(ipython console)' and IDLE gives
'pyshell#0' whereas running from a module gives its filename. This
seems a bit hacky. Any better ideas?

--
Dan Goodman

http://thesamovar.net/contact

[Jeff]

Re: How to tell if I'm being run from a shell or a module

Conventionally, you use:

if __name__ == '__main__':
# do something as a script

[Chris]

Re: How to tell if I'm being run from a shell or a module

On Feb 14, 7:21 pm, dg.google.gro.. .@thesamovar.ne t wrote:

Hi all,
>
Is there any standard way to tell if the user is running from a module
or from an interactive shell like IDLE or IPython? The best I've come
up with so far is for a function to look at
getouterframes( currentframe())[1][1] (the filename in the frame record
of the frame that called the function), and check if it exists or not
with os.path.exists. IPython gives '(ipython console)' and IDLE gives
'pyshell#0' whereas running from a module gives its filename. This
seems a bit hacky. Any better ideas?
>
--
Dan Goodmanhttp://thesamovar.net/contact

If you're just trying to prevent some actions from happening if
something loads your script as a module just put the 'action items'
under an if like:
if __name__ == '__main__':
do_the_cool_stu ff()

All your functions inside the file will remain in-tact but it won't
execute anything.

[dg.google.groups@thesamovar.net]

Re: How to tell if I'm being run from a shell or a module

Thanks for the replies, but it's not what I meant. What I want to be
able to determine is whether or not the user is running from an
interactive shell (like IPython or IDLE). Checking if
__name__=='__ma in__' checks if the current module is the one being
run, but suppose you have two modules A and B, with the function f
defined in module B that should print 'Interactive' or 'Module' say.
The module A just consists of: import B; B.f(). Now whenever f is
called, __name__ will not be '__main__' for it. Someone using IDLE
could write import B then B.f() too. The question is: is there a way
for f to determine if someone was using an interactive shell to call
it or if it was being called some other way. The way I came up with
works in these limited cases but won't work in a more general
situation (but perhaps there is no way for it to know in the more
general situation).

Dan

On Feb 14, 7:01 pm, Chris <cwi...@gmail.c omwrote:

If you're just trying to prevent some actions from happening if
something loads your script as a module just put the 'action items'
under an if like:
if __name__ == '__main__':
do_the_cool_stu ff()
>
All your functions inside the file will remain in-tact but it won't
execute anything.

[Gabriel Genellina]

Re: How to tell if I'm being run from a shell or a module

En Thu, 14 Feb 2008 19:09:10 -0200, <dg.google.grou ps@thesamovar.n et>
escribió:

Thanks for the replies, but it's not what I meant. What I want to be
able to determine is whether or not the user is running from an
interactive shell (like IPython or IDLE). Checking if
__name__=='__ma in__' checks if the current module is the one being
run, but suppose you have two modules A and B, with the function f
defined in module B that should print 'Interactive' or 'Module' say.
The module A just consists of: import B; B.f(). Now whenever f is
called, __name__ will not be '__main__' for it. Someone using IDLE
could write import B then B.f() too. The question is: is there a way
for f to determine if someone was using an interactive shell to call
it or if it was being called some other way. The way I came up with
works in these limited cases but won't work in a more general
situation (but perhaps there is no way for it to know in the more
general situation).

It depends on what you mean by "an interactive shell"? If you start your
script with:
python -i whatever.py
is it an interactive shell or not?

I tried these two criteria:
a) See if the __main__ module has a __file__ attribute.
b) See if sys.stdin is a real tty

These are the results I got on Windows for several configurations:

<test.py>
import sys
print "__main__ has __file__", hasattr(sys.mod ules['__main__'], '__file__')
import os
print "sys.stdin is a tty", hasattr(sys.std in, "fileno") and
os.isatty(sys.s tdin.fileno())
</test.py>

python test.py
__main__ has __file__ True
sys.stdin is a tty True

python -i test.py
__main__ has __file__ True
sys.stdin is a tty True

python test.py <nul >nul
__main__ has __file__ True
sys.stdin is a tty True

python test.py <emptyfile >nul
__main__ has __file__ True
sys.stdin is a tty False

pythonw.exe (the consoleless Python executable for Windows)
__main__ has __file__ True
sys.stdin is a tty False

IDLE
__main__ has __file__ False
sys.stdin is a tty False

pythonwin.exe
__main__ has __file__ False
sys.stdin is a tty False


--
Gabriel Genellina

[Sion Arrowsmith]

Re: How to tell if I'm being run from a shell or a module

Gabriel Genellina <gagsl-py2@yahoo.com.a rwrote:

>a) See if the __main__ module has a __file__ attribute.
>b) See if sys.stdin is a real tty

c) See if sys.argv[0] != ''

(Although this works for the command line interactive shell, I've a
suspicion it will fail with IDLE. But I don't have IDLE to hand to
check.)

--
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