Re: [Matplotlib-users] Using the lasso tool when file is not main

[Tony Yu <ts...@gm...>]

On Wed, Sep 5, 2012 at 7:19 PM, Mark Budde <mar...@gm...> wrote:

> Hi,
> I'm not an expert so please go easy on me. I am using the pyplot lasso
> demo, and have got it to work how I would like. I am having a problem,
> however, where I cannot get it to work if my python file is not the
> main file (where __name__ is not __main__).
>
> I took the part at the bottom in the "if __name__ == '__main__':" and
> put it into a class. Everything works fine if I call the class from
> within the same file. However, if I call the class from another file,
> the graph loads fine but the lasso tool does not work. Troubleshooting
> revealed that LassoManager.onpress is not being called when I click
> the mouse. Any suggestions are welcome because this is driving me
> crazy!
> Thanks,
> Mark
>
>
Hi Mark,

I can't seem to reproduce your issue, but it's a bit difficult without
seeing how exactly you wrapped up the "main" part of the code. Just
guessing: maybe the two cases aren't *exactly* the same.

Is it possible that you have ``lman`` (the LassoManager instance) defined
in the same block of code as ``show`` in one case but not the other? If,
for example, ``lman`` is defined in a method of your class, but not saved
anywhere then it'll get discarded after the method finishes. So ``show``
would need to be called inside that method, or saved as a class attribute.

Like I said, that's just a wild guess. You should paste the class def if
you're still having problems.

Best
-Tony

P.S. If you're running matplotlib from Github master, you might be
interested in an alternative lasso tool  (LassoSelector) that may be
simpler to use.:
https://github.com/matplotlib/matplotlib/blob/master/examples/widgets/lasso_selector_demo.py