How do *you* use Python in non-GUI work?

[David C. Ullrich]

On Sun, 18 May 2008 18:20:22 -0400, John Salerno
<johnjsal at NOSPAMgmail.com> wrote:

>Hey all. Just thought I'd ask a general question for my own interest. Every time I think of something I might do in Python, it usually involves creating a GUI interface, so I was wondering what kind of work you all do with Python that does *not* involve any GUI work. This could be any little scripts you write for your own benefit, or what you do at work, if you feel like talking about that! :)

You might get a keyboard with an Enter key, btw. Anyway:

I'm a math professor, not a programmer.
I use Python probably every day to do
all sorts of things, for example:

(i) Calculating grades. (Ok, this could be done in
Excel. But if you know Python anyway you don't need
to figure out how to do various things in Excel.
Quick: In Excel how do you take all the quiz
scores, drop the lowest _two_ of them and average
the rest? Stumps people sometimes - if you're
doing it by hand in Python it's no problem, you
just do it.)

(ii) Every semester I get a lot of emails asking
about grades. Used to be tedious typing the same
replies over and over, looking up the relevant
numbers. A littls Python script takes the student's
name, looks up the numbers and generates a reply
automatically, including a summary of the scores
and an explanation of how the grade was calculated.)

(iii) Taking various data from various places and making
it into HTML to post on the department web site.
(Please don't look - a lot of that stuff is currently
broken due to improvements on the server introduced
by other faculty. These things happen when nobody's
in charge so things get done by whoever's willing
to do them...)

(iv) Say I want to display the following system
of equations on a quiz:

  3x + 2y + z = 3
   x      - z = 1.

Writing TeX to get the variables to line
up properly can be tedious. A little Python
thingie takes lists of variable names and
coefficients and automatically produces
TeX that displays the equations exactly right.

I could go on and on - I use computers for a lot
of things, and any time I want to do something
but it's not obvious how to do it in the relevant
big program Python gets pulled out to do the job. 

A meta-example: I'm about to publish a book on 
[never mind, the topic is still secret.] Python 
has been incredibly useful in writing that book, 
in many different ways. For example:

(v) Making modifications to the text itself. For
example, the other day I finally figured out how
to make a certain aspect of the thing look right.
So I wanted to replace every "$$[w]\qed" in the
text (where [w] denotes any amount of white space)
with "\QED$$". Took about a minute to make a Python
script to go through the entire book and make the
change.

(vi) There are a lot of figures. Some fairly
complicated, illustrating fairly complicated
mathematical things. The figures are eps files
that were generated by Python scripts. The simple
ones could just have easily been done in Adobe
Illustrator or Corel Whatever, but there's no
way you're going to use a mouse-based program
like that to draw the complicated figures and
have everything in exactly the right place.
I have Python do the calculations and then
write the corresponding eps file, done.

(vii) Many magical things were done with a
combination of TeX macros and Python scripts.
For example, index entries: If I say
\index{Some Theorem} in the text and it turns
out that that's on page 37 then
"Some Theorem p.37" appears in the index;
now if something gets revised so the
\index{Some Theorem} is now on page 38 then
the index entry is automatically revised to
page 38.

Or: The first page of Chapter n+1 is supposed
to be the smallest odd number larger than the
last page of Chapter n. A Python script typesets
("texs") each chapter; after typesetting Chapter
n it looks and sees what the last page is,
figures out what the first page of Chapter n+1
should be, and modifies the code for Chapter n+1
to start on the page before typesetting it.

If I wrote this tomorrow the list of examples
would be different. Just now over on 
comp.text.tex I showed someone a Python solution
to a problem he had. I don't know if he's going 
to use it - he _would_ need to learn a _little_
Python first. But it's what I'd use if _I_ wanted
to solve the problem! Other people suggested various
programs available that would solve his problem
for him - writing a little Python to give the
solution took less time than downloading one
of those programs would have.

>Thanks.

David C. Ullrich