Hello David,
It look like you're trying to create a brain for astroid. Here's a recent
example for signal directly in astroid recently :
https://github.com/PyCQA/astroid/pull/1172/files
Hope this helps :)
Le mar. 5 oct. 2021 à 14:26, David Rajaratnam <da...@gemarex.com.au> a
écrit :
> Hi all,
>
> I'm trying to write a transform plugin to better work with a library that
> I maintain. For background my library extends a third-party library and
> uses some dynamic typing to add new features and wrappers on top of the
> third-party library. Because it uses dynamically created classes pylint
> complains about having missing members (E1101) and unexpected keyword
> arguments in the constructor (E1123).
>
> The class that is being dynamically generated only gets generated once
> when the module is imported and provides a proxy/wrapper around an existing
> class from the third-party library. The wrapper mirrors the member
> functions from the original class, as well as overriding and adding some
> new member functions. So the structure is something like:
>
>
> tpmodule.py
>
> # third-party library
>
> class Control:
> ....
>
>
> mymodule.py
>
> # my library
>
> import tpmodule
>
> def _make_wrapper(towrap):
> .... # dynamically create new class
>
> Control = _make_wrapper(tpmodule.Control)
>
>
> user.py
>
> # user code to run pylint on
>
> import mymodule
>
> ctrl = Control(...)
> ctrl.original_func(...)
> ctrl.new_func(...)
>
>
> My plan with the transform plugin is to use
> 'astroid.MANAGER.register_transform()' to detect the 'astroid.Module' calls
> and turn 'mymodule.py' into something more palatable for pylint; in
> particular to replace 'mymodule.Control' with an 'astroid.ClassDef' that
> has the correct initializer and member functions. Unfortunately, things are
> not working the way I would like and I'm still getting the missing member
> and bad constructor arguments errors, even though, as far as I can see, I
> am returning the appropriately modified module.
>
> However, there are many things that I don't understand:
>
> 1) Relating to the above example, pylint seems to be treating the 'ctrl'
> variable in 'user.py' 'ctrl' as being of type 'tpmodule.Control' so doesn't
> complain about things that are common to 'tpmodule.Control' and
> 'mymodule.Control'. But I cannot understand how pylint could possibly
> detect the relationship between 'tpmodule.Control' and 'mymodule.Control'
> without getting into the guts of the 'mymodule._make_wrapper()' function.
>
> 2) It is not clear to me how pylint treats imports from external
> libraries? In my example tpmodule.py and mymodule.py are not things that I
> want pylint to report on. But presumably it still needs to follow some of
> the chain of dependencies to work out the signature of what is exposed by
> the module so I understand why it would parse 'mymodule.py', but I don't
> understand why it would parse 'tpmodule.py'.
>
> In fact, another curious thing is that I created a cut down example to
> highlight the problem and while it has some of the same errors it also
> behaves slightly differently. In the cut-down example pylint DOESN'T
> actually parse 'tpmodule.py' so 'tpmodule.Control' doesn't trigger the
> 'register_transform()' the way it does in the real system. Even though this
> makes more sense to me than what is happening in the actual code, it is
> unfortunate because I wanted to dynamically construct the signature of
> 'tpmodule.Control' so was relying on pylint parsing 'tpmodule.py'.
>
> Note for clarification, in the real system 'mymodule.py' and 'tpmodule.py'
> are more complex and both use functions from their respective internal
> modules. 'tpmodule.py' is actually written in C++ and is using CFFI to
> generate the Python API, so maybe that can explain some difference in the
> behaviour to the pylint expert?
>
> Anyway, I'm sorry for the long winded questions. However, I'm hoping
> someone has someone insight or can point me to some docs or a specific
> example that solves a similar issue. I can also post a zip file of my cut
> down example if it is appropriate to do so. It consists of four short files
> ('mymodule.py', 'tpmodule.py', 'user.py', and 'plugin.py').
>
>
> Regards,
>
> Dave
>
>
>
>
>
>
> To be clear I'm not using pylint on the library itself, instead I want
> pylint to work nicely with users of the library; although at some point I
> will try to configure pylint to help me with refactoring some of the code
> as well.
>
>
> My library extends an existing library with some new feature. and does
> some dynamic typing.
>
>
> I'm new to the group and
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