Is there a need for range(len(a))?
If you need to work with indices of a sequence, then yes – you use it… eg for the equivalent of numpy.argsort…: >>> a = [6, 3, 1, 2, 5, 4] >>> sorted(range(len(a)), key=a.__getitem__) [2, 3, 1, 5, 4, 0]
range
Is there a range class in C++11 for use with range based for loops?
The C++ standard library does not have one, but Boost.Range has boost::counting_range, which certainly qualifies. You could also use boost::irange, which is a bit more focused in scope. C++20’s range library will allow you to do this via view::iota(start, end).
In Kotlin can I create a range that counts backwards?
Use downTo as in: for (n in 100 downTo 1) { // }
Is there a reason that we cannot iterate on “reverse Range” in ruby?
A range is just that: something defined by its start and end, not by its contents. “Iterating” over a range doesn’t really make sense in a general case. Consider, for example, how you would “iterate” over the range produced by two dates. Would you iterate by day? by month? by year? by week? It’s not … Read more
How to create range in Swift?
Updated for Swift 4 Swift ranges are more complex than NSRange, and they didn’t get any easier in Swift 3. If you want to try to understand the reasoning behind some of this complexity, read this and this. I’ll just show you how to create them and when you might use them. Closed Ranges: a…b … Read more
Identify groups of continuous numbers in a list
EDIT 2: To answer the OP new requirement ranges = [] for key, group in groupby(enumerate(data), lambda (index, item): index – item): group = map(itemgetter(1), group) if len(group) > 1: ranges.append(xrange(group[0], group[-1])) else: ranges.append(group[0]) Output: [xrange(2, 5), xrange(12, 17), 20] You can replace xrange with range or any other custom class. Python docs have a … Read more
How does one make random number between range for arc4random_uniform()?
I believe you should do dice1 = arc4random_uniform(6) + 1; to get the range 1 – 6. I don’t do iOS objective C nor have I any knowledge on swift-language though. The random method should return a value between 0 and 5, and + 1 will make it a value between 1 and 6. If … Read more
Select data from date range between two dates
As you can see, there are two ways to get things done: enlist all acceptable options exclude all wrong options Obviously, second way is much more simple (only two cases against four). Your SQL will look like: SELECT * FROM Product_sales WHERE NOT (From_date > @RangeTill OR To_date < @RangeFrom)
swift convert Range to [Int]
You need to create an Array<Int> using the Range<Int> rather than casting it. let intArray: [Int] = Array(min…max)
Difference between ‘..’ (double-dot) and ‘…’ (triple-dot) in range generation?
The documentation for Range† says this: Ranges constructed using .. run from the beginning to the end inclusively. Those created using … exclude the end value. So a..b is like a <= x <= b, whereas a…b is like a <= x < b. Note that, while to_a on a Range of integers gives a … Read more