Guidance on initialization code in a module

[mrstevegross]

Is there a common way to initialize various stuff in a module? That
is, I have some code in my module that I want to run whenever the
module is imported. Currently, my module looks like this:

=== foo.py ===
def something():
...

def somethingelse():
...

something()
=== EOF ===

Is the 'something()' line at the end in an ok location? I just put it
at the end. Maybe there's some special __init__() mechanism for
modules? Or should I use the 'if __name__ != '__main__'' trick?

Thanks,
--Steve

 

[Dave Angel]

Is there a common way to initialize various stuff in a module? That
is, I have some code in my module that I want to run whenever the
module is imported. Currently, my module looks like this:

=== foo.py ===
def something():
...

def somethingelse():
...

something()
=== EOF ===

Is the 'something()' line at the end in an ok location? I just put it
at the end. Maybe there's some special __init__() mechanism for
modules? Or should I use the 'if __name__ != '__main__'' trick?

Thanks,
--Steve

You're doing fine. Everything in the module is run when it's imported.
Running a definition, of course, compiles it, and adds its name to the
module's namespace. But anything outside of a definition or class, or
other qualifier will just be run.

If the module will never be used as a script, the if __name__ == logic
isn't needed. If you want this initialization code to be run *only* if
it's not being run as a script, then you'd do as you suggest, if
__name__ != "__main__"

But usually, the initialization code wants to be run whether it's being
used as a script, or as a library module. So leave the conditional off,
till you actually decide what behavior should be conditional.

 

[David Stanek]

Is there a common way to initialize various stuff in a module? That
is, I have some code in my module that I want to run whenever the
module is imported. Currently, my module looks like this:

=== foo.py ===
def something():
 ...

def somethingelse():
 ...

something()
=== EOF ===

Is the 'something()' line at the end in an ok location? I just put it
at the end. Maybe there's some special __init__() mechanism for
modules? Or should I use the 'if __name__ != '__main__'' trick?

I think what you are doing is fine. The only thing that I would do
differently is rename 'something' to 'initialize'. That way your
intent is really obvious.