Hmm. You mention having<p>> ...Another reason to preallocate Python lists when possible.<p>But how would one do that? I mean, you could do `list(range(10000))` which would in a sense pre-allocate a 10000-element list. But, does the `list()` operation look ahead and make a list that size at once, or does it just keep appending the next item from the iterable, going through the 12% expansions multiple times?<p>Also, I can't think offhand of an iterable that would generate N identical "empty" list items. Like 10000 zeros or 10000 Nones. Anyone?