tuples

问题 I want unzip list of tuples in a column of a pyspark dataframe Let's say a column as [(blue, 0.5), (red, 0.1), (green, 0.7)] , I want to split into two columns, with first column as [blue, red, green] and second column as [0.5, 0.1, 0.7] +-----+-------------------------------------------+ |Topic| Tokens | +-----+-------------------------------------------+ | 1| ('blue', 0.5),('red', 0.1),('green', 0.7)| | 2| ('red', 0.9),('cyan', 0.5),('white', 0.4)| +-----+-----------------------------------

问题 I have the following two arrays: let xaxis = ["monday", "tuesday", "wednesday", "thursday", "friday"] let yaxis = [1, 2, 3, 4, 5] I would like to merge them into an array that looks like this: [ ("monday", 1), ("tuesday", 2), ("wednesday", 3), ("thursday", 4), ("friday", 5)] 回答1: Use zip and map : let xaxis = ["monday", "tuesday", "wednesday", "thursday", "friday"] let yaxis = [1, 2, 3, 4, 5] let tuples = zip(xaxis, yaxis).map { ($0, $1) } 回答2: Try this: let xaxis = ["monday", "tuesday",

问题 I have the following two arrays: let xaxis = ["monday", "tuesday", "wednesday", "thursday", "friday"] let yaxis = [1, 2, 3, 4, 5] I would like to merge them into an array that looks like this: [ ("monday", 1), ("tuesday", 2), ("wednesday", 3), ("thursday", 4), ("friday", 5)] 回答1: Use zip and map : let xaxis = ["monday", "tuesday", "wednesday", "thursday", "friday"] let yaxis = [1, 2, 3, 4, 5] let tuples = zip(xaxis, yaxis).map { ($0, $1) } 回答2: Try this: let xaxis = ["monday", "tuesday",

问题 Currently I'm doing this: def getJSONString(lst): join = "" rs = "{" for i in lst: rs += join + '"' + str(i[0]) + '":"' + str(i[1]) + '"' join = "," return rs + "}" which I call like: rs = getJSONString([("name", "value"), ("name2", "value2")]) It doesn't need to be nested (it's only ever going to be a simple list of name value pairs). But I am open to calling the function differently. It all seems a bit cludgy, is there a more elegant way? This needs to run under 2.x. Note that this is not a

问题 Currently I'm doing this: def getJSONString(lst): join = "" rs = "{" for i in lst: rs += join + '"' + str(i[0]) + '":"' + str(i[1]) + '"' join = "," return rs + "}" which I call like: rs = getJSONString([("name", "value"), ("name2", "value2")]) It doesn't need to be nested (it's only ever going to be a simple list of name value pairs). But I am open to calling the function differently. It all seems a bit cludgy, is there a more elegant way? This needs to run under 2.x. Note that this is not a

问题 My basic idea was to derive my own class from std::tuple to get some helper types inside like this: template <typename ... T> class TypeContainer: public std::tuple<T...> { public: using BaseType = std::tuple<T...>; static const size_t Size = sizeof...(T); TypeContainer(T... args):std::tuple<T...>(args...){}; using index_sequence = std::index_sequence_for<T...>; }; Now I try to use the code as follows: using MyType_tuple_with_empty = std::tuple< std::tuple<float,int>, std::tuple<>, std::tuple

问题 Just for curiosity, it's not a 'I must have it', but how declare a tuple using system.tuple class in powershell? I'm using powershell.exe.config to load framework 4.0 but I'm not able to create a tuple. Trying this: PS C:\ps1> $a = [System.Tuple``2]::Create( "pino", 34) Chiamata al metodo non riuscita. [System.Tuple`2] non contiene un metodo denominato 'Create'. In riga:1 car:31 + $a = [System.Tuple``2]::Create <<<< ( "pino", 34) + CategoryInfo : InvalidOperation: (Create:String) [],

问题 If I have a tuple like this var answer: (number: Int, good: Bool) How do I get one of the elements? This doesn't work: answer["number"] I am modeling this question after Swift: Get an array of element from an array of tuples, but my question was a little more basic. I did find the answer buried in the documentation so I am adding my answer below in Q&A format for faster searching in the future. 回答1: According to the documentation (scroll down to Tuples), there are three ways to do it. Given

问题 I'd like to know how are tuple implemented in standard library for C++0x. I tried to read description in libstdc++ manual and then read template listing, but it's really hard to understand how it works, especially when reading code. Can someone explain me in few sentences the idea of tuple implementation? I want to know this, because I thinking about using tuples in my code and i want to understand how it works and what type of overhead does it brings (extends compile time only, perform many

问题 Why does nobody seem to use tuples in C++, either the Boost Tuple Library or the standard library for TR1? I have read a lot of C++ code, and very rarely do I see the use of tuples, but I often see lots of places where tuples would solve many problems (usually returning multiple values from functions). Tuples allow you to do all kinds of cool things like this: tie(a,b) = make_tuple(b,a); //swap a and b That is certainly better than this: temp=a; a=b; b=temp; Of course you could always do this