Parsing of a file

[Mike Driscoll]

On Aug 6, 1:55 pm, Tommy Grav <tg... at mac.com> wrote:
> I have a file with the format
>
> Field f29227: Ra=20:23:46.54 Dec=+67:30:00.0 MJD=53370.06797690 Frames  
> 5 Set 1
> Field f31448: Ra=20:24:58.13 Dec=+79:39:43.9 MJD=53370.06811620 Frames  
> 5 Set 2
> Field f31226: Ra=20:24:45.50 Dec=+78:26:45.2 MJD=53370.06823860 Frames  
> 5 Set 3
> Field f31004: Ra=20:25:05.28 Dec=+77:13:46.9 MJD=53370.06836020 Frames  
> 5 Set 4
> Field f30782: Ra=20:25:51.94 Dec=+76:00:48.6 MJD=53370.06848210 Frames  
> 5 Set 5
> Field f30560: Ra=20:27:01.82 Dec=+74:47:50.3 MJD=53370.06860400 Frames  
> 5 Set 6
> Field f30338: Ra=20:28:32.35 Dec=+73:34:52.0 MJD=53370.06872620 Frames  
> 5 Set 7
> Field f30116: Ra=20:30:21.70 Dec=+72:21:53.6 MJD=53370.06884890 Frames  
> 5 Set 8
> Field f29894: Ra=20:32:28.54 Dec=+71:08:55.0 MJD=53370.06897070 Frames  
> 5 Set 9
> Field f29672: Ra=20:34:51.89 Dec=+69:55:56.6 MJD=53370.06909350 Frames  
> 5 Set 10
>
> I would like to parse this file by extracting the field id, ra, dec  
> and mjd for each line. It is
> not, however, certain that the width of each value of the field id,  
> ra, dec or mjd is the same
> in each line. Is there a way to do this such that even if there was a  
> line where Ra=****** and
> MJD=******** was swapped it would be parsed correctly?
>
> Cheers
>    Tommy

I'm sure Python can handle this. Try the PyParsing module or learn
Python regular expression syntax.

http://pyparsing.wikispaces.com/

You could probably do it very crudely by just iterating over each line
and then using the string's find() method.

Mike