Python on

Python thread dumps.

Wed, 17 Dec 2008 00:00:00 +0000

For some time I’ve wanted the equivalent of Java’s ability to dump the stack trace of all currently running threads in Python as a means for debugging some hung processes. I finally found a solution and wired it up to the services’ http console:

import sys
import traceback
from pygments import highlight
from pygments.lexers import PythonLexer
from pygments.formatters import HtmlFormatter

def stacktraces():
    code = []
    for threadId, stack in sys._current_frames().items():
        code.append("\n# ThreadID: %s" % threadId)
        for filename, lineno, name, line in traceback.extract_stack(stack):
            code.append('File: "%s", line %d, in %s' % (filename, lineno, name))
            if line:
                code.append("  %s" % (line.strip()))

    return highlight("\n".join(code), PythonLexer(), HtmlFormatter(
      full=False,
      # style="native",
      noclasses=True))

The magic happens with sys._current_frames() which returns exactly what I wanted. The only outstanding issue is how to get the thread’s name to display in addition to the ident.

Albums, predicates, SmugMug, pysmug v0.5.

Tue, 14 Oct 2008 00:00:00 +0000

I have a lot of SmugMug albums and sometimes I have a hard time tracking down in which Category and SubCategory one resides or whether I’ve updated all the albums to use square thumbnails – thus was born smugfind.

I just released version 0.5 of pysmug which includes smugfind and some minor bug fixes. It’s available here for download or through hg (courtesy freehg):

$ hg clone -r v0.5 http://freehg.org/u/bzimmer/pysmug/

To show help:

$ smugfind -h
Usage: smugfind [options]

Options:
  -h, --help            show this help message and exit
  -s, --sharegroups     display sharegroup
  -f FIELDS, --fields=FIELDS
                        list of fields to display for each entity
  -l, --list            available list of fields to display
  -p PREDICATE, --predicate=PREDICATE
                        predicate to evaluate

To see all the possible metadata fields:

pysmug, tag clouds, asynch IO and the SmugMug API.

Thu, 12 Jun 2008 00:00:00 +0000

A question was asked on a dgrin thread about whether the SmugMug API supported building a tag cloud – it doesn’t. A responder suggested it would take far too long to generate one from the API since you’d have to trawl through every photo. This is indeed true, but you don’t have to do it serially. I consider the batchable interface for pysmug to be it’s selling point and building a tag cloud is the perfect demonstration.

pysmug on Python2.6a3.

Fri, 16 May 2008 00:00:00 +0000

I decided tonight was the night to try Python2.6a3 on my macbook pro with a goal of getting pysmug to run on it.

After downloading and doing the typical configure && make dance I saw this:

Failed to find the necessary bits to build these modules:
bsddb185          gdbm              linuxaudiodev
ossaudiodev       readline          spwd
sunaudiodev

Apparently setup.py won’t build the readline module with the stock readline library on my mac. I already installed libreadline from MacPorts so I applied the following patch:

pysmug 0.4 released.

Wed, 14 May 2008 00:00:00 +0000

I just released version 0.4 of pysmug and I’m pretty happy with the additional functionality.

The most significant additions to the ChangeLog referenced in my previous post are the migration of examples to tests and the overhauled configuration file format for pysmug.login().

tests

I’m generally a proponent of testing but since so much of pysmug is dependent on SmugMug services I added examples rather than tests. That’s changed with v0.4 – the examples have either been converted to code in SmugTool and/or migrated to a test case. I took the opportunity to learn nose and I’m not upset with the decision. When I switched from in-function preparing of SmugMug-style parameters names to using a decorator it was nice to have the tests to back me up.

Python decorators.

Wed, 14 May 2008 00:00:00 +0000

I finally found a non-trivial reason to implement a Python decorator. I make extensive use of Python keyword arguments in the pysmug API and map those spellings to SmugMug keyword arguments. The algorithm for converting a Python spelling to a SmugMug spelling is pretty straight forward and easily wrapped up in a function. Originally, the first line of every function required formatting the keywords into SmugMug-style spellings by calling self._prepare_keywords(**kwargs). It occurred to me this is a perfect use case for decorators so I converted the code from a class method to a function, moved the call up a line, prefixed a @ and voilà, a far more explicit communication about how this method handles keyword arguments – love it.

pysmug version 0.4 coming soon

Sun, 11 May 2008 00:00:00 +0000

While I hammer away at erlsmug and try to figure out why it’s so much slower than pysmug and PycURL, I’m ready to release version 0.4 of pysmug.

Among the biggest changes are compatibility with new security changes required for version 1.2.2 of the SmugMug API. It’s now also possible to register function callbacks for PycURL’s verbose and progress handlers.

In testing erlsmug’s concurrency, I wrote a function to return all the details of an album as well as the details about each image, including EXIF. This requires 1 call to get the album info, 1 call to get the images for an album and one call each for simple and EXIF details per image. This function, albums_details was so useful I wanted it for pysmug.