Spyder: Color scheme changes after kernel restart

[amccaugh]

Description

The color scheme shown in the console window changes after you restart the kernel

What steps will reproduce the problem?

1. Open a new IPython console
2. Cause an error (run an undefined function "prin")
3. Observe the color scheme -- as expected
4. Restart that console's kernel (I used ctrl-.)
5. Cause an error (run an undefined function "prin")
6. Observe the color scheme -- has now changed to very bright colors

Versions and main components

• Spyder Version: 3.2.6
• Python Version: 3.6.3
• Qt Version: 5.6.2
• PyQt Version: 5.6
• Operating system: Windows

Dependencies

IPython >=4.0 : 6.1.0 (OK)
cython >=0.21 : 0.26.1 (OK)
jedi >=0.9.0 : 0.10.2 (OK)
nbconvert >=4.0 : 5.3.1 (OK)
numpy >=1.7 : 1.13.3 (OK)
pandas >=0.13.1 : 0.22.0 (OK)
pycodestyle >=2.3: 2.3.1 (OK)
pyflakes >=0.6.0 : 1.6.0 (OK)
pygments >=2.0 : 2.2.0 (OK)
pylint >=0.25 : 1.7.4 (OK)
qtconsole >=4.2.0: 4.3.1 (OK)
rope >=0.9.4 : 0.10.5 (OK)
sphinx >=0.6.6 : 1.6.3 (OK)
sympy >=0.7.3 : 1.1.1 (OK)

[ccordoba12]

Thanks for reporting. We'll take a look at this in a future release.

[csabella]

Confirmed this is happening on Windows 7, but it is not happening on Ubuntu.

Found the magic command %colors. If %colors linux is entered, then it uses the very bright colors. If %colors lightbg is used, then it looks normal. So, for some reason, on Windows, when the kernel is restarted, the color scheme is changing from lightbg to linux, but on Ubuntu, it is not changing.

[ccordoba12]

@csabella, do you have time to take a look at this one?

[csabella]

@ccordoba12 I started taking a look at this, but it's a mystery so far. There are two places in the Spyder code where %colors is invoked, but using debug_print on Ubuntu, those methods aren't called during a kernel reset. I need to check debug_print on Windows, but I'm also thinking that this may be happening in qtconsole and not Spyder. I need to do some more digging.

[csabella]

I believe this was caused by IPython pull requests 10260 (https://github.com/ipython/ipython/pull/10260), 10281, and 9838, but I can't install a version before 5.3.0 to check it out. Probably the best thing for Spyder to do would be to call the overrides of the %colors on a restart.

EDIT: I was able to downgrade to IPython 5.1.0 and it did not happen on that version, so I am certain those were the pull requests that introduced this.

[ccordoba12]

Probably the best thing for Spyder to do would be to call the overrides of the %colors on a restart.

What do you mean by that?

[csabella]

What do you mean by that?

I apologize; I've been looking at debug_print so much that I knew what I meant. :-)

In the IPython console, in client.py, there is a method called configure_shellwidget with the following:

        if not create_qss_style(self.shellwidget.syntax_style)[1]:
            self.shellwidget.silent_execute("%colors linux")
        else:
            self.shellwidget.silent_execute("%colors lightbg")

When a Spyder is first opened or when a new console is created, this code is called. However, it is not called on a restart of the kernel. It would seem that the IPython defaults take over and change the color settings in the console. So I was thinking that maybe we need to execute this on a restart.

[ccordoba12]

Ok, good call! Could you open a PR with that insight? Thanks!