Efficiently finding the last line in a text file [duplicate]

Question

I need to extract the last line from a number of very large (several hundred megabyte) text files to get certain data. Currently, I am using python to cycle through all the lines until the file is empty and then I process the last line returned, but I am certain there is a more efficient way to do this.

What is the best way to retrieve just the last line of a text file using python?

Answer 1

Not the straight forward way, but probably much faster than a simple Python implementation:

line = subprocess.check_output(['tail', '-1', filename]) 

Answer 2

with open('output.txt', 'r') as f:     lines = f.read().splitlines()     last_line = lines[-1]     print last_line