Provide pylint plugin to avoid warnings in IDE when working with conanfile.py

Problem

When editing conanfile.py with editor which has linter support (VS Code with Python extension in my case) there are a bunch of errors related to dynamic fields (like self.copy is not callable or Instance of ConanFile doesn't have package_folder member).

Proposal

Conan has a built-in linting support for conanfile.py, but it deals with dynamic fields by post-processing json output.

It would be useful if this logic is moved to a pylint plugin which can be reused by editor/IDE or via command line options.

There are few tutorials on the Internet about how to do it.

[ytimenkov]

@mmatrosov It works better if you install conan via pip. If you have standalone installer which provides python modules (not sure if the official one does, pyinstaller explicitly hides modules so they can’t be imported) you can add it to sys.path. For example my .pylintrc looks like:

[MASTER]
init-hook='import sys; sys.path.extend(["/home/user/conan-install"])'

load-plugins=conans.client.conanfile_plugin

[MESSAGES CONTROL]
disable=C,R

(the plugin is in PR yet)

[memsharded]

Hi all!

Many thanks to @ytimenkov for implementing it! It will be released in next 1.6, keep tuned for testing it!