Python object overhead?

Mark Nenadov mark at
Sat Mar 24 00:31:17 CET 2007

On Fri, 23 Mar 2007 19:11:23 -0300, Gabriel Genellina wrote:

> Poor xreadlines method had a short life: it was born on Python 2.1 and got  
> deprecated on 2.3 :(
> A file is now its own line iterator:
> f = open(...)
> for line in f:
>    ...


Thanks for pointing that out! I had completely forgotten about

I've tested them before. readlines() is very slow. The deprecated
xreadlines() is close in speed to open() as an iterator. In my particular
test, I found the following:

readlines() -> 32 "time units"
xreadlines() -> 0.7 "time units"
open() iterator -> 0.41 "time units"

Mark Nenadov -> skype: marknenadov, web:
-> "They need not trust me right away simply because the British say 
that I am O.K.; but they are so ridiculous. Microphones everywhere 
and planted so obviously. Why, if I bend over to smell a bowl of 
flowers, I scratch my nose on a microphone."
-- Tricyle (Dushko Popov) on American Intelligence

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