How do i read just the last line of a text file?

[Andy Leszczynski]

Chris F.A. Johnson wrote:
> On Sun, 29 May 2005 at 05:57 GMT, John Machin wrote:
> 
>>Chris F.A. Johnson wrote:
>>
>>
>>>file = open(argv[1])          ## Open the file given on the command line
>>>all_lines = file.readlines()  ## Read all the lines
>>
>>I see your shadowing and raise you one obfuscation:
> 
> 
>    ;)
> 
> 
>>open = file(argv[1])          ## File the open given on the command line
>>all_lines = open.readlines()  ## Read all the lines
> 
> 
>    Such verbosity! (I excuse mine on the grounds that it was my first
>    attempt at a Python program.)
> 
> all_lines = file(argv[1]).readlines()
> 
>    And to answer the question in the subject line:
> 
> last_line = file(argv[1]).readlines()[-1]
> 
>    Both of which assume "from sys import argv".
> 
> 
>    Now I have to get serious and forget those bad habits.
> 

What if a file is long enough?

A.