Grep in Python

[Stefan Kirchberg]

coolslife wrote:

>>>I saw that lots of people have implemented their own version of grep
>>>and most have called it "pygrep". (Am I right about that?). Since this
>>>is a resource consuming activity,  does anyone have any idea what
>>>might be a optimum way to implement this?


>>See "NR-grep: A Fast and Flexible Pattern Matching Tool", by Gonzalo
>>Navarro, at http://www.dcc.uchile.cl/~gnavarro/ps/spe01.ps.gz for how
>>to search text fast.
> 
> Thanx for your replies.

> are there any other resources I can look up?

Since grep uses Regular Expressions, you might want to have a look at 
the standard module 're'. One could try something like the following 
example. It's quite simple (because it's Python ;-)

 >>>>>>>>>>>>>>>>snip
import re, sys

# your search expression here, maybe
pat = sys.argv[1]

# your input text filename, maybe
fname = sys.argv[2]

# now scan the textfile
for line in open("C:/temp/test.txt").readlines():
   if re.search(pat, line):
     print line,

# that's it.
<<<<<<<<<<<<<<<<snap

Hope this helps. Sure it's not perfect... ;-)

   Stefan