Le Mon, 11 May 2009 19:09:30 -0700 (PDT),
nickel flipper <nickelflip...@yahoo.com> s'exprima ainsi:
>
> Hello,
> Just getting started with Python, and have had some early, although trivial
> success. It looks like just the ticket to parse a data file. Total noob at
> this, but really kind of overwhelmed by all the options. Looking for some
> direction on which modules, librarys, or ? to accomplish the goal.
>
> To date have been using conditional type statement to tease out
> information. Now I need to match some strings, put them in an array or
> list? and read them back after X number of lines. The linesplits are in a
> predictable pattern and padded by '-' to get eight values or arrays that
> will be joined together after a set condition is no longer true.
>
> So from the data set below, will be looking to print out:
> RA7,OSC1,CLKI
> RA6,OSC2
> RA5,AN4,nSS1,LVDIN,RCV,RP2
> ETC.
>
> Any tips greatly appreciated. Thanks.
>
>
> sfr (key=PORTA addr=0xf80 size=1 access='rw rw rw u rw rw rw rw')
> reset (por='xxxxxxxx' mclr='uuuuuuuu')
> bit (names='RA7 RA6 RA5 - RA3 RA2 RA1 RA0' width='1 1 1 1 1 1 1 1')
> bit (tag=scl names='RA' width='8')
> bit (names='OSC1 OSC2 AN4 - AN3 AN2 AN1 AN0' width='1 1 1 1 1 1 1 1')
> bit (names='CLKI CLKO nSS1 - VREF_PLUS VREF_MINUS C2INA C1INA' width='1
> 1 1 1 1 1 1 1') bit (names='- - LVDIN - C1INB CVREF_MINUS PMPA7 PMPA6'
> width='1 1 1 1 1 1 1 1') bit (names='- - RCV - - C2INB RP1 RP0' width='1 1
> 1 1 1 1 1 1') bit (names='- - RP2 - - - - -' width='1 1 1 1 1 1 1 1')
>
> Here is some noob code used to pick out the RA7, RA6, RA5 etc. Comments
> welcome.
>
> if line.startswith ( " bit (names='R" ):
> (a, pin7, pin6, pin5, pin4, pin3, pin2, pin1, pin0) = (line.split()
> + ["", ""])[:9] startpin = pin7[8:3]
> if startpin.startswith == "RA" or "RB" or "RC" or "RD" or "RE" or
> "RF" or "RG" or "RH" or "RJ": print pin7[8:] + "," + pin6 + "," + pin5 +
> "," + pin4 + "," + pin3 + "," + pin2 + "," + pin1 + "," + pin0[:3] + "\n"
> else: pass
Hem, rather complicated. I would use a regex for once in this precise case. But
forget it if you're not used to regexes, rather take the opportunity to learn
python builtin strings methods better.
Anyway, as a step on the regex path, the following code
s = """\
sfr (key=PORTA addr=0xf80 size=1 access='rw rw rw u rw rw rw rw')
reset (por='xxxxxxxx' mclr='uuuuuuuu')
bit (names='RA7 RA6 RA5 - RA3 RA2 RA1 RA0' width='1 1 1 1 1 1 1 1')
bit (tag=scl names='RA' width='8')
bit (names='OSC1 OSC2 AN4 - AN3 AN2 AN1 AN0' width='1 1 1 1 1 1 1 1')
bit (names='CLKI CLKO nSS1 - VREF_PLUS VREF_MINUS C2INA C1INA' width='1 1 1
1 1 1 1 1')
bit (names='- - LVDIN - C1INB CVREF_MINUS PMPA7 PMPA6' width='1 1 1 1 1 1 1
1')
bit (names='- - RCV - - C2INB RP1 RP0' width='1 1 1 1 1 1 1 1')
bit (names='- - RP2 - - - - -' width='1 1 1 1 1 1 1 1')"""
from re import compile as Pattern
p = Pattern(r"names='((?:(?:\w+|-) ?){8})'")
r = p.findall(s)
print r
outputs
['RA7 RA6 RA5 - RA3 RA2 RA1 RA0', 'OSC1 OSC2 AN4 - AN3 AN2 AN1 AN0', 'CLKI CLKO
nSS1 - VREF_PLUS VREF_MINUS C2INA C1INA', '- - LVDIN - C1INB CVREF_MINUS PMPA7
PMPA6', '- - RCV - - C2INB RP1 RP0', '- - RP2 - - - - -']
As you see the pattern is hardly legible. It matches a sequence of 8 'things'
inside "names='...'. Each 'thing' is either an alphanumeric string or '-',
possibly followed by a space. (Actually it's not fully correct.) We have to use
twice so-called non-grouping parentheses "(?:...)". What is actually captured
is inside simple (...).
Denis
------
la vita e estrany
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
