27.01.2011, 15:55, "Roy Smith" <[email protected]>: > In article <[email protected]>;, > Alice Bevan–McGregor <[email protected]>; wrote: > >> On 2011-01-26 02:59:26 -0800, Xavier Heruacles said: >>> I have do some log processing which is usually huge. The length of each >>> line is variable. How can I get the last line?? Don't tell me to use >>> readlines or something like linecache... >> This is not optimum or efficient, but it works! If you want to see >> what's going on, use 4 instead of 4096 and 8 instead of 8192 and add a >> print statement to the bottom of the while loop. :) >> >> import os >> >> with open('biglogfile.log', 'r') as fh: >> fh.seek(-4096, os.SEEK_END) >> buffer = fh.read(4096) >> >> # We are expecting a trailing newline. >> while "\n" not in buffer[:-1]: >> fh.seek(-8192, os.SEEK_CUR) >> buffer = fh.read(4096) + buffer >> >> # Eliminate empty lines, they aren't useful. >> lines = [line for line in buffer.split('\n') if line] >> print lines[-1] >> >> — Alice. :) > > Back in the old days, if you wanted to read a file backwards, you just > used a tape drive that had read-reverse capability :-) > > -- > http://mail.python.org/mailman/listinfo/python-list
Yeah. And if you wanted to zoom image -- you just had to go couple steps closer to it) -- jabber: [email protected] -- http://mail.python.org/mailman/listinfo/python-list
