Fix most flake8 complaints for src/ folder

[bittner]

Theses changes address almost all flake8 complaints in the src/ folder.

[bittner]

This is really bad: The Travis CI stable image runs on Debian Trusty, which sports neither python-wxgtk3.0 nor python3-wxgtk4.0. We have to install python-wxgtk2.8, but this doesn't seem to install the wx Python 2 module in a way to make Pylint recognize its existance, e.g.

************* Module src.pythonturtle
E:  7, 0: Unable to import 'wx' (import-error)
E:  8, 0: Unable to import 'wx.aui' (import-error)
E:  9, 0: Unable to import 'wx.lib.buttons' (import-error)
E: 10, 0: Unable to import 'wx.lib.scrolledpanel' (import-error)

This also makes clear that we need to test running PythonTurtle against several target distributions, and operating systems later.

It probably makes sense to switch to Docker-based builds, and prepare a Docker image with wxPython for each and every combination of wxPython + distro, to make things easier.

[bittner]

I opened an issue in the wxPython project issue tracker. This will probably lead to a more lengthy discussion and/or implementation effort. But that's the only direction that makes sense, IMHO.

[bittner]

Let me try using the Travis Xenial-based infrastructure before merging. Hang on!

[bittner]

Using Xenial works out for Python 2.7 only. 😒 I'll revert the commit.

[cool-RR]

By the way, I think that Windows is the most popular os for PythonTurtle users. I don't know whether that's relevant to what you're doing there, but just FYI.

…

On Mon, Sep 17, 2018, 13:24 Peter Bittner ***@***.***> wrote: Using Xenial works out for Python 2.7 only. 😒 I'll revert the commit. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#105 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AADdypowmbH-iue8UaZywO23qh2Yj-5Oks5ub3hOgaJpZM4Wq8JL> .

[bittner]

Well, it's relevant for me. I made my kids play with PythonTurtle, they have Dell notebooks running Ubuntu 18.04 LTS Bionic. They impress others (students and teachers) at school. That's what I want to happen: That teachers are impressed and that students are motivated to play with Python. Otherwise they use some other, really awkward LOGO-like language environments that favor semicolons and allow mixing UPPERcase and lowERcasE keywords. (No, thank you!)

Can you open an issue where we collect all the information for running Windows and macOS builds? I want to prepare the infrastructure for building installer packages also for Windows and macOS, but my main focus will be on GNU/Linux (.deb, .rpm, snap packages). If we manage to collect all the commands that make Windows builds (probably on AppVeyor, not sure though) and builds for macOS happen (on either Travis CI, Circle CI, or GitLab) -- fine. But I can't and won't do trouble shooting for those non-free platforms.

You may want to look into the feature set of AppVeyor, and open a free OSS project account with them. Would be nice to run everything off a single platform, but I don't see that they support builds on macOS. Maybe you find out.

[bittner]

@cool-RR This is really bad style. There must be a better way to compute and deal with the "current working directory" and such. (See related flake8 complaint.)

Currently, this is unsolved. I think we have to refactor the project, though, to improve the situation.

Also, the project - from Python's point of view - is currently called src. This is due to __init__.py being in the src folder. No good. This asks for being fixed.

[bittner]

Maybe we can do some collaborative programming to solve that in #106. Would be nice!

[bittner]

Other than the above issue (that we can fix later, with a separate effort) this PR is ready to be merged.

[bittner]

You can merge this PR now, if you want. Thank you!