perl to python

[Duncan Booth]

Kirk Job-Sluder <kirk at eyegor.jobsluder.net> wrote in
news:slrnca0ub4.1bdc.kirk at eyegor.jobsluder.net: 

> The above code runs, but is not very good because I'm not that
> familiar with exec statements.  Anyway I've tried to capture what
> "perl -pi -e" actually does which is to execute an arbitrary command
> over every line of an arbitrary list of files, editing them in place,
> with a temporary backup copy.

Your code might have been a bit shorter if you had used the existing 
facility in Python for editing files in place. The code below is completely 
untested, so I can all but guarantee it doesn't work, but you get the idea:

#!/usr/local/bin/python
import getopt,sys,os,re
import fileinput 
 
#get your command line options 
#files will be in  
optlist, args = getopt.getopt(sys.argv[1:],'e:')
 
for line in fileinput.input(args, inplace=1):
    #execute all of the -e statements. 
    for command in optlist: 
        #warning bad mojo here 
        foo=(command[1] % line.rstrip("\n"))
        exec(("line=%s" % foo)) 
    #save to the new file
    print line

fileinput.close()