A short look

Well, almost missed my narrow window of code time… Was passed out on the couch with a full stomach before bed until nearly 0100 xD

Between My mom, my sister, the bird, and my nephew (a louder bird)… And helping with baking there is really not much I can do during the day.. Any attempt at even thinking about seriously trying to read or write goes out the window and in comes a headache. So I have to work at night, when every one else is alseep… Until I crash or the clock reaches a point where I need to go to sleep in order to be @ work on time.

I completed the mock up of a simple dialog for simulating make config. And I’ve almost finished a working prototype for the module but I don’t have time to handle writing the slots and associated code to deal with the check boxes right now. And I need to get that done and tested before I can incorporate the prototype unto the module it belongs.

I posted a screen shot of the mock up awhile back. I’ve fixed the display a bit (the leading variable name from the makefile is removed). And added an ok and cancel button with the beginnings of a more key-board friendly behavior when it comes to using the keys instead of the rat to use it hehe. I’ve also set the caption on the dialog to contain the ports name as category/program.

In doing this, I figured the most simple way was to just muck around with a string of our target (e.g. /usr/ports/net/samba3 and /usr/ports/www/links/ in my tests). Although now that I think of it, the same routine I wrote to get a list of options to create check boxes for. Could be used to look up the category and portname variables from the makefile instead because it’s not tied to looking up any specific variable. — TODO: compare both methods for speed
after the prototype is ready to be moved to alpha group.

In trying to figure out how to get the desired result from a string version of our working path, I remembered that most languages offer some way to obtain the basename of a file or directory and set to look for it in Pythons os module. But doing that would mean we’d have to cut off the trailing slash and refeed the path to the library routine then join them into a new thing. Not exactly my idea of fun when writing a quick helper subroutine. I was very happy that help(os.path.split) revealed a method that takes care of most of that legwork itself.

Python also has some thing called list compression and which allows the mapping of the contents from one list into another based on given criteria. I’ve generally avoided list compressions out of disfavor for some of the (large) examples I’ve seen before. But for this, I actually found it yielded both quick to write and easy to understand code.

p = name # '/usr/ports/category/program' for example
prog = os.path.split(p)
cat = os.path.split(prog[0])

path = ["%s/%s" % (c,p) for c,p in zip(cat, prog) if c and p]
return path.pop()

The above snippet splits name into two lists of two elements, each a string. Basically the 2nd line returns a list of [‘/usr/ports/category’, ‘program’]. So obviously line 3 likewise splits /usr/ports/category into a list of two elements, the last of which is category. I really love how os.path.split() speeds up reading this, it takes only a glance to read it without having to double check it.

The 5th line maps any elements of the two lists (cat and prog) into a single a list of strings, i.e. some thing like path => [ ‘/usr/ports/category’, ‘category/program’ ]. The test for each element being true could be ommited in this case but I wanted to show the possibility.

Since path is a list and we want to display a string (without using str() on the result!), we just pop() the last element off path, which is exactly the element we want ‘category/program’

mm, now for some sleep… It’s after 5am here and I’m exhausted.

1 thought on “A short look”

  1. Originally posted on my Live Journal:

    by: (Anonymous) at 2007-12-17 07:19 pm (UTC)
    comment: don't you have a public library or something ?

    by: sas_spidey01 at 2007-12-17 10:37 pm (UTC)
    comment: It's far outside of walking distance, lacks a wireless AP, and I don't have a drivers license =/

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