colored error messages for "larch -r -c"

[bruceravel]

I am leaving an issue rather than making a pull request because I am pretty sure the hack I made is not the best way to implement what I am looking for. It is very handy that the larch server can be made to echo with the -c flag. However, finding the error among a mountain of text is rather difficult. So I modified lib/larchlib.py in two ways. First, at the top, I did

  from termcolor import colored

then, as the return for get_error, I did

  return (exc_name, colored('\n'.join(out), 'red'))

Very helpful for troubleshooting Athena!

I have no idea whether that'll work on Windows. And you may want to use a command line flag or some other configuration to turn the coloring on and off. Also, it seems that termcolor is not part of a standard python installation, so it would have to be a recommended dependency. In short, I'm just not sure the best way to implement this.

It may be a more broadly useful dependency, though. Some color in the REPL may be quite nice.

I should say that I used termcolor because it was the first suggestion in an article on Stack Overflow

[newville]

I'm completely willing to add that as a "use if available" option, and add termcolor as a recommended option.
Will work on it.

[maurov]

For a simple string color print without any dependence, here my two cents:

https://github.com/maurov/larch_plugins/blob/master/std/cprint.py

I simply translated in Python what we do here at ESRF under SPEC. Maybe it is not elegant, but it works under Linux, no idea under Windows.

[newville]

Hi Mauro, Bruce,

On Mon, Nov 25, 2013 at 2:20 AM, Mauro Rovezzi notifications@github.comwrote:

For a simple string color print without any dependence, here my two cents:

https://github.com/maurov/larch_plugins/blob/master/std/cprint.py

I simply translated in Python what we do here at ESRF under SPEC. Maybe it
is not elegant, but it works under Linux, no idea under Windows.

Thanks. I think termcolor does (mostly?) the same sort of thing, inserting
the same kind of color-codes. Do you know how they differ.... I'm open to
either approach.

The termcolor module does not work with a plain MS Windows shell (cmd.exe),
or even with Powershell (which can colorize text, but I have no idea how).
It may work with cygwin.

Anyway, getting this to work on Windows would be a bit of work, but that
doesn't mean it shouldn't be a "use if available" option. I added
user-level options, so that one can set
_sys.errortext_color ('red', 'grey', 'green', 'yellow', 'blue',
'magenta', 'cyan')
_sys.errortext_bold True/False
_sys.errortext_dark True/False
_sys.errortext_underline True/False
_sys.errortext_blink True/False
_sys.errortext_reverse True/False

at any time to alter the results. it seems that not all of these options
actually work for all terminals/systems.

[bruceravel]

This claims to work on Windows:

https://pypi.python.org/pypi/colorama

[bruceravel]

Matt, thanks for implementing this so quickly. I really wish I had thought to ask for this ages ago. So much easier to debug Athena!

[newville]

Hmm, I just downloaded and tried this and it totally put Python in an
infinite loop, needing to be killed from TaskManager.... I haven't
investigated further, but this looks to be not ready for prime time.

Those of us who sometimes develop on Windows are doomed. I myself often
have a linux shell opened to the windows folder I'm testing in. But
having all the devel tools for Windows is better. Then again, using a
better shell would be helpful too...