What was the project that made you feel skilled in Python?

[Roy Smith]

In article <mailman.1844.1368963057.3114.python-list at python.org>,
 Ned Batchelder <ned at nedbatchelder.com> wrote:

> So here's a question for people who remember coming up from beginner: as 
> you moved from exercises like those in Learn Python the Hard Way, up to 
> your own self-guided work on small projects, what project were you 
> working on that made you feel independent and skilled?  What program 
> first felt like your own work rather than an exercise the teacher had 
> assigned?

IIRC, my first production python projects were a bunch of file parsers.  
We had a bunch of text file formats that we worked with often.  I wrote 
some state-machine based parsers which slurped them up and gave back the 
contents in some useful data structure.

Many of the files were big, so I added an option to write out a pickled 
version of the data.  The parsing code could then check to see if there 
was a pickle file that was newer than the text version and read that 
instead.  Big win for speed.

Then, of course, a bunch of utilities which used this data to do useful 
things.  I remember one of the utilities that turned out to be really 
popular was a smart data file differ.  You feed it two files and it 
would tell you how they differed (in a way that was more useful than a 
plain text-based diff).