Mike Meyer wrote:
Ok, we've added list comprehensions to the language, and seen that they were good. We've added generator expressions to the language, and seen that they were good as well.
I'm left a bit confused, though - when would I use a list comp instead of a generator expression if I'm going to require 2.4 anyway?
Never. If you really need a list
list(x*x for x in xrange(10))
Not quite true. If you discovered the unlikely scenario that the construction of a list from the generator expression was an efficiency bottleneck, you might choose a list comprehension -- they're slightly faster when you really do want a list:
$ python -m timeit "list(x*x for x in xrange(10))" 100000 loops, best of 3: 6.54 usec per loop
$ python -m timeit "[x*x for x in xrange(10)]" 100000 loops, best of 3: 5.08 usec per loop
STeVe -- http://mail.python.org/mailman/listinfo/python-list
