Writing more efficient code

[gonzlobo]

Greetings, and happyNewYear to all.

I picked up Python a few weeks ago, and have been able to parse large
files and process data pretty easily, but I believe my code isn't too
efficient. I'm hoping dictionaries will help out, but I'm not sure the
best way to implement them.

I've been using a bunch of nested if/elif/else statements to select
slices (0317 & 03de) from a file, then parse the data (aa, hh, bb,
d2-d9) into parameters (a = airspeed, h = heading) & flags.

#sample file contents
0000007d 03 0317 aa aa aa aa aa hh hh hh bb bb
0000007e 06 03de d2 d3 d4 d5 d6 d7 d8 d9 10 11

# some pseudo code
if PID == '03de':
    flapsCmd = int(d3, 16)
   if flapsCmd == 0xc0:
      <flaps up code>
   elif flapsCmd == 0x03:
      <flaps down code>
if PID == '0317':
   airspeed == 'combine aa for airspeed & multiply by 0.1'
   heading == 'combine hh for heading'
   mach == 'combine bb for mach & multiply by 0.01'

Might dictionaries help in this case... say Label0317(parameterName,
slice (d3), scaleFactor(0.1))... I'd like to use them if they'll
replace the dozens of nested conditionals.  I have roughly 75
different parameters to decode from a file containing ~2.5 million
lines of data.

I know my pseudo code lacks details, but hopefully I'm getting my
point across...

(I suppose switch/select/case statements would help a bit, but python
doesn't seem to use them... not to start a religious war or anything).

Any help (or encouragement) is appreciated.