python过滤器无法输出

Question

i create filter by python to the log file like

    Sat Jun  2 03:32:13 2012 [pid 12461] CONNECT: Client "66.249.68.236"
    Sat Jun  2 03:32:13 2012 [pid 12460] [ftp] OK LOGIN: Client "66.249.68.236", anon     password "gxxglxxxxt@google.com"
    Sat Jun  2 03:32:14 2012 [pid 12462] [ftp] OK DOWNLOAD: Client "66.249.68.236",   "/pub/10.5524/100001_101000/100022/readme.txt", 451 bytes, 1.39Kbyte/sec

the script is

import time
f= open("/opt/CLiMB/Storage1/log/vsftp.log")
def OnlyRecent(line):
    if  time.strptime(line.split("[")[0].strip(),"%a %b %d %H:%M:%S %Y") < time.time()-(60*60*24*2):
       return True
    return False

for line in f:
      if OnlyRecent(line):
         print line

f.close()

but when i run this script, it didn't show anything. Why it can't shows records happened in 2 days. And Since the log file is very large, and records are sorted by time, so how to speed up to find records.

Thanks

Answer 1

This script won't print anything until it has fully processed the entire file in memory because of the final join.

If you want to print as it goes, use a loop and print for each line returned by the filter.

import time
f = open("/opt/CLiMB/Storage1/log/vsftp.log")
f.readline() # Not sure why you're doing this, but retained to replicate behaviour

def OnlyRecent(line):
    if time.strptime(line.split("[")[0].strip(),"%a %b %d %H:%M:%S %Y") < time.time()-(60*60*24*2):
       return True
    return False

for line in f:
    if OnlyRecent(line):
        print line

f.close()

Answer 2

You are comparing two different data structures. time.strptime() returns a struct time. Whereas, time.time() gives time in seconds since epoch.

You can use the time.gmtime function to convert time since epoch to a time structure and then compare or use calendar.gmtime to convert struct time to time since epoch and then compare.