Category: Programming

A big part of my work has to do with code. I’ve worked as system administrator – installing, patching, and configuring someone else’s code. I’ve worked as independent programmer, writing code on my own. I also programmed as part of the team. And on top of that, I worked as Team Leader and Project Manager, where I had to interact a lot with programmers. Programming world on its own is as huge as the universe. There is always something to learn. When I find something worthy or something that I understand enough to write about, I share it in this category.

I can’t believe I did it so fast

Remember how I mentioned Python only yesterday? Well, I’ve had a really long (and fun) programming session (about 10 hours), and I have a warm feeling of deep familiarity with the language. Yup, I know it. I am surprised though. It usually took me much longer to learn the language.

Of course, I can’t claim that I know it all. Here are the things that I used in the last few hours:

Lists and dictionaries
Functions (with parameters and default values) and objects
Database interaction (MySQL with MySQLdb)
Forking
Regular expressions
Documenting code … Really.

I wrote and re-wrote almost a 1000 lines of code, which made me feel much more comfortable with Python syntax and concepts.

P.S.: I still got it…

Python! Here I come!

Life is full of surprises and irony. Or at least it looks so to me. Especially now.

It’s been more than two years since I planned to learn Python programming language. At first I really wanted to do so, but didn’t have any free time. Then I came across a couple of tasks at work that made me write a few patches here and there, but the complexity just wasn’t there and I didn’t learn anything beyond the simpliest things. Then a lot of time passed by and I forgot those simpliest things too.

Recently I found myself looking at Python code more often than I used to. But I still didn’t have to write any code. Just read and understand.

Then I had to write few more patches. Again, the complexity wasn’t there.

And so on and so forth.

Until today I realized that I have a somewhat complex project to implement and there is practically no choice of programming language. Hooray! I’ll finally have to learn to use Python!

P.S.: I’m glad I was saving up all those Python bookmarks.

RegExp reminder

I was just reminded about this small thing, which is so easy to forget – regular expressions that have markers of line start (^) and/or line end($) are so much faster than those regexps that don’t have these markers. The thing is that with line start/end marker regexp engine needs to make only one match/substution, whereas when there is no such markers, it has to repeat the match/substitution operation at every character of the string.

In practice, it’s unbelievable how much difference this can make. Especially when using complex regular expressions over large data sets.

P.S.: I understand that it is not always possible to use these markers, but I think that they can be used much more often than they are. Everywhere.

The answer to “Why Not Python?”

Collin Park has written an article in four parts (one, two, three, and four) titled “Why Not Python?”. I’ve read through the first couple of parts and scrolled through the rest.

In all that text that passed in front of my eyes I haven’t found the answer to the question. I guess, it wasn’t actually the question after all then.

Well, in case you read asked yourself “Why Not Python?”, I’ll give one of the possible answers. Because it is too complicated. Python might do OK as the first progarmming language for those of you who want to learn programming concepts. But if you have a problem at hand that needs solving, Perl is the way to go in most of the cases.

Example. Collin Park uses the Sudoku game solver as one of the examples. Fine task. Nice one to learn how to program too. But if you just have a Sudoku game to solve (or a few for that matter), than it would be much faster to do it in Perl. Here is how.

Navigate your browser to search.cpan.org.
Type in “sudoku”, choose “Modules” and press “Search CPAN”.
With this particular example, any module from the search result can be used. With other examples, you want really want to review the module description (one line that says what module does). So, this step is, choose the one module that seems to be appropriate for your problem.
Install chosen module, by running cpan command from root shell and typing in install module::name (substitute “module::name” with the name of the module you chose in the previous step).
Run perldoc module::name to see module documentation and example of used.
Copy the code from SYNOPSIS are of documentation in your favourite editor.
Save the file
Run the script

Tada! You’re all done.

If it takes you more than 15 minutes, chances are – you are doing something wrong. Of course, your mileage may vary, but 15 minutes is somewhere near the lighthouse.

Decimal to binary convertion in Perl

This is a simple thing, but when you need it – you need it. There is no need in implementing a function that does or looking for a module at CPAN. All you are looking for is already there.

#!/usr/bin/perl -w

use strict;

# Get the number from the command line or use default.
my $number = shift || 42;

printf "%b\n", $number;

You might want to refresh you memory of printf or sprintf by flipping though the manual pages.

P.S.: 42 decimal = 101010 binary. Is it cool or what?