Parse ASCII log ; sort and keep most recent entries

[Nova's Taylor]

Wow - thanks for all of your great suggestions.  I did neglect to
mention that the log file is appended to over time, so the values are
already in a time-sequenced sort going in, thus allowing the use of a
dictionary as suggested by David and others. This is what I wound up
using:

sourceFile = open(r'C:\_sandbox\SASAdmin\Python\ServerAdmin\SignOnLog.txt')

# output file for testing only 
logFile = open(r'C:\_sandbox\SASAdmin\Python\ServerAdmin\test.txt',
'w')

piddict = {}
for line in sourceFile:
        pid,username,date,time = line.split()
        piddict[pid] = (username,date,time)

pidlist = piddict.keys()
pidlist.sort()
for pid in pidlist:
        username,date,time = piddict[pid]
         # next line seems amateurish, but that is what I am!
        logFile.write(pid + " " + username + " " + date + "" + time +
"\n")

More background:

I will next merge this log file to process identifiers running on a
server, so I can identify "who-started-what-process-when." In Perl I
do it this way:


$pattern=sas;  ## name of application I am searching for

# Use PSLIST.EXE to list processes on the server 
open(PIDLIST, "pslist |") or die "Can not run the PSLIST program:
$!\n";

while(<PIDLIST>)
{
  $output .=$_;
  if (/$pattern/i) 
  {
    ## collect pids that match pattern into an array, splitting on
white spaces
    @taskList=split(/\s+/, $_);
    
    ## Check each value in the Server task list with each row in the
log file
    foreach $proc_val ( @fl ) 
     {
       chomp($proc_val); ## Remove new line characters at the end.
       @log=split(/\s+/, $proc_val);

       if ( $log[0] eq $taskList[1])
       {
       	  # print">>>>No matches in log Files!!<<<<<<<<<<< \n";  #
debug
       	  print "$taskList[0]     $log[0] $log[1]  $log[2]
$taskList[5] $log[3] $taskList[8] \n";
       	  $foundIt=1;
       }
    }
  }
} 
close(PIDLIST);
 

So now its more reading to see how to do this in Python! 
Thanks again for all your help!

Taylor