Deleting lines in XYZ file?

[athomo]

First off, is it possible to write a script to delete certain lines within an XYZ file; I've only be able to find ways to delete rows within a table.

You see, I used Python (and a previously compiled script) to convert an ASCII file into an XYZ file (pretty cool!), but now i've got an 90mb file with z- values of -9999 that need to be deleted along with the corresponding x- and y- values. Note, I am unable to delete the -9999 values before conversion because then the ASCII to XYZ script would not run properly.

Any suggestions on how to run this -- sort first and then delete? make a table?

Here's an example file:
mydata.xyz
112.45,33.58,345.2
112.85,33.95,405.2
112.65,33.54,-9999 (...need this entire row deleted)
112.85,33.24,302.6

Thanks for any input you can give!

 

[ericbrunson]

You would have to open the file, iterate through it, find the lines you want to keep and write them out to another file.

import csv

p = csv.reader( open( "mydata.xyz" ) )
o = open( "newdata.xyz", "w" )

for row in p:
  if row[2] != "-9999":
    o.write( ",".join( row ) . "\n" )

(I just wrote this off the top of my head, it isn't tested, but it should give you a start)

 

[athomo]

Thanks so much ~ the only change to this script was replacing a . with + as shown:

( row ) . "\n" )
with
( row ) + "\n" )

and it worked perfectly!

now it's time to play!! thanks again!

 

[ericbrunson]

Oh, right. I've been switching back and forth from PHP too much.