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14,136 Pointsxrange vs _ in range
_ in range was used in the datetime course - for a more memory efficient loop. How does this differ from xrange - which I've heard is used for a similar purpose?
3 Answers
Mikael Enarsson
7,056 Pointsxrange() apparently does not exist in python 3., but range() does what it used to do (discussed here).
Anyway, I don't know if this is more to the point of your question, but what, for example, for _ in range(n) does is perform the code inside the code block once for every element in the range, but doesn't bother to store the value, thus saving precious memory. I don't know the internals, but there it is.
Kenneth Love
Treehouse Guest TeacherMikael Enarsson has it right. It's more memory-efficient because it doesn't store the current value of the loop. In Python 2, most of the time you wanted to use xrange() because it's a generator instead of a list, like range() was. In Python 3, plain ol' range() is a generator so there's no reason to use (or even have) xrange().
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14,136 PointsOk thanks for the explanations - I need to go and find out more about generators (vs iterators) as I haven't really covered what they are yet.
Thanks.