Ry4an's Unblog

Tag: python (Atom feed)

Mercurial Chart Extension

Back in 2008 I wote an extension for Mercurial to render activity charts like this one:

Yesterday I finally got around to updating it for modern Mercurial builds, including 2.1. It's posted on bitbucket and has a page on the Mercurial wiki. It uses pygooglechart as a wrapper around the excellent Google image chart API.

I really like the google image charts becuse the entire image is encapsulated as a URL, which means they work great with command line tools. A script can output a URL, my terminal can make it a link, and I can bring it up in a browser window w/o ever really using a GUI tool at all.

If I take any next step on this hg-chart-extension it will be to accept revsets for complex secifications of what changesets one wants graphed, but given that it took me two years to fix breakage that happened with version 1.4 that seems unlikely.

Published: Feb 12, 2012 3:10:11 AM by Ry4an Brase
Tags: mercurial, python, ideas-built
Permalink - Source code

Asynchronous Python Logging

The Python logging module has some nice built-in LogHandlers that do network IO, but I couldn't square with having HTTP POSTs and SMTP sends in web response threads. I didn't find an asynchronous logging wrapper, so I wrote a decorator of sorts using the really nifty monkey patching availble in python:

def patchAsyncEmit(handler):
    base_emit = handler.emit
    queue = Queue.Queue()
    def loop():
        while True:
            record = queue.get(True) # blocks
            try :
                base_emit(record)
            except: # not much you can do when your logger is broken
                print sys.exc_info(
    thread = threading.Thread(target=loop)
    thread.daemon = True
    thread.start(
    def asyncEmit(record):
        queue.put(record)
    handler.emit = asyncEmit
    return handler

In a more traditional OO language I'd do that with extension or a dynamic proxy, and in Scala I'd do it as a trait, but this saved me having to write delegates for all the other methods in LogHandler.

Did I miss this in the standard logging stuff, does everyone roll their own, or is everyone else okay doing remote logging in a web thread?

Published: Sep 27, 2011 4:50:34 AM by Ry4an Brase
Tags: python, ideas-built, software
Permalink - Source code

Syntax Highlighting and Formulas for Blohg

I'm thus far thrilled with blohg as a blogging platform. I've got a large post I'm finishing up now with quite a few snippets of source code in two different programming languages. I was hoping to use the excellent SyntaxHighlighter javascript library to prettify those snippets, and was surprised to find that docutils reStructuredText doesn't yet do that (though some other implementations do).

Fortunately, adding new rendering directives to reStructuredText is incredibly easy. I was able to add support for a .. code mode with just this little bit of Python: