Paddy wrote: > the del version - is that an optimisation? > Is it actually faster?
del x[-1:] # or del x[-1] if you are sure that len(x) > 0 just deletes the last item (if any) from x whereas x = x[:-1] copies all but the last item of the original list into a new one. This can take much longer: [copy 10000 lists with 5000 items on average] $ python -m timeit -n10000 -s'data = range(10000)' 'data = data[:-1]' 10000 loops, best of 3: 38.9 usec per loop [remove the last item from a list 10000 times] $ python -m timeit -n10000 -s'data = range(10000)' 'del data[-1:]' 10000 loops, best of 3: 0.272 usec per loop $ python -m timeit -n10000 -s'data = range(10000)' 'del data[-1]' 10000 loops, best of 3: 0.246 usec per loop Peter -- http://mail.python.org/mailman/listinfo/python-list
