Deprecating vs rewriting was 50/50. I was for deprecating because plotfile() does too much and is beyond the scope of matplotlib. It's a chance to cut back on our API.

Disregarding my personal preference, something has to be done about plotfile(). Unless someone volunteers to rewrite it, this deprecation is the practical way to go.

I'll officially change my "vote" in #12180. I think plotfile should go away. Parsing a file is well outside of matplotlib's scope, and much better handled by other libraries.

IF an example is changed, I'd prefer the example uses numpy.csvread or whatever, and then does the plotting in native plotting commands. If we want to show the user how to write a "plotfile" wrapper for a certain format of file, that would be great.

@anntzer can you please rebase on top of master. I'm not sure if I would break things for you if I rebase and then add a commit to enhance the example.

rebased

Added some more explanation. Once plotfile is removed, this can be converted to a general "plotting data from files" example.

I'll put in a vote for deprecation:

1. The status quo is untenable--we can't be relying on other API's we've deprecated
2. The idea behind plotfile is not a good one, it goes back to trying to do everything
3. A quick, nonexhaustive check for plt.plotfile on GitHub either gives me false positives or forks of the plotfile_demo.py script

So I'm with @timhoffm. Also, if we deprecate and people scream, we can revisit.

@timhoffm Are there critical changes needed for this, or can it be merged as-is?

From my side, this is good enough. We've added a number of examples how to achieve the same functionality as plotfile using numpy or pandas.