pairs from a list

[bearophileHUGS at lycos.com]

Alan Isaac>What is the fastest way? (Ignore the import time.)<

Maybe someday someone will realize such stuff belongs to the python
STD lib...

If you need a lazy generator without padding, that splits starting
from the start, then this is the faster to me if n is close to 2:

def xpartition(seq, n=2):
    return izip( *(iter(seq),)*n )

If you need the faster greedy version without padding then there are
two answers, one for Psyco and one for Python without... :-)
If you need padding or to start from the end then there are more
answers...

Bye,
bearophile