tuples

问题 I have this tuple of tuples: TupleOfTuples = (('Venue1', 'Name1'), ('Venue1', 'Name2'), ('Venue2', 'Name3'), ('Venue3', 'Name4'), ('Venue3', 'Name5'), ('Venue3', 'Name6')) I want to convert it to get a result like this: Output = (('Venue1', 2), ('Venue2', 1), ('Venue3', 3)) In this case, Output contains ('Venue1', 2) , for example, where 2 is the number of times 'Venue1' occurred in TupleOfTuples . I tried using len() to count the number of occurrences, but it does not work given that

问题 I'm trying to covert a list of coordinates to a list of tuples: from: a_list = ['56,78','72,67','55,66'] to: list_of_tuples = [(56,78),(72,67),(55,66)] I've tried doing a for, in loop to convert each element in a_list to a tuple however the output is in the form: list_of_tuples = [('5', '6', '7', '8'), ('7', '2', '6', '7'), ('5', '5', '6', '6')] Any help on what I am doing wrong here would be greatly appreciated. EDIT: Fixed the expected output, no spaces between coordinates and tuples. 回答1:

问题 This question already has answers here : Possible to initialize multiple variables from a tuple? (7 answers) Closed 4 years ago . In Python we can unroll a tuple with similar syntax: a, b = (1, 2) Is there are similar structure in C#? Or accessing elements like: Tuple<int, int> t = Tuple.Create(1, 2); Console.Write(t.Item1); the only possible way? 回答1: Tuple destructuring (sometimes called "explosion"), i.e. distributing its elements over several variables, is not directly supported by the C#

问题 In discussion of this answer we realized that tuples do not have a __reversed__ method. My guess was that creating the iterator would require mutating the tuple. And yet tuples play fine with reversed . Why can't the approach used for reversed be made to work for __reversed__ as well? >>> foo = range(3) >>> foo [0, 1, 2] >>> list(foo.__reversed__()) [2, 1, 0] >>> foo [0, 1, 2] >>> bar = (0, 1, 2) >>> list(bar.__reversed__()) Traceback (most recent call last): File "<stdin>", line 1, in

问题 I'm trying to make a list which is used throughout the application immutable. I thought wrapping this list in a tuple would do the trick, but it seems that tuple(list) doesn't actually wrap, but copies the list elements. >>> a = [1, 2, 3, 4] >>> b = tuple(a) >>> b (1, 2, 3, 4) >>> a[0] = 2 >>> b # was hoping b[0] to be 2 (1, 2, 3, 4) Is there an easy way of creating a list-backed "view" on this list that is immutable (wrt. operations on this view), but reflects any change that happened to the

问题 I have this: interface Obj { foo: string, bar: number, baz: boolean } The desired type is this tuple: [string, number, boolean] How can I convert the interface to the tuple? Update: My original problem is: I make some opinionated library with a declarative spirit, where a user should describe parameters of a function in an object literal. Like this: let paramsDeclaration = { param1: { value: REQUIRED<string>(), shape: (v) => typeof v === 'string' && v.length < 10 }, param2: { value: OPTIONAL

问题 When assigning a tuple of, say, Int members, to a tuple of an (heterogeneous) protocol type, to which Int conforms, it is seemingly only allowed to perform this assignment via explicit member-by-member assignment. protocol MyType {} extension Int: MyType {} let intPair = (1, 2) var myTypePair : (MyType, MyType) // OK myTypePair = (intPair.0, intPair.1) // OK let intPairToMyTypePair : ((Int, Int)) -> (MyType, MyType) = { ($0.0, $0.1) } myTypePair = intPairToMyTypePair(intPair) // For all below

问题 I first started C++ with Microsoft VC++ in VS2010. I recently found some work, but I've been using RHEL 5 with GCC. My code is mostly native C++, but I've noticed one thing... GCC doesn't appear to recognize the <tuple> header file, or the tuple template. At first I thought maybe it's just a typo, until I looked at cplusplus.com and found that the header is indeed not part of the standard library. The problem is that I like to write my code in Visual Studio because the environment is way

问题 I'm parsing HTML and I need to get only tags with selector like div.content . For parsing I'm using HTMLParser. I'm so far that I get list of tags' attributes. It looks something like this: [('class', 'content'), ('title', 'source')] The problem is that I don't know how to check that: List have tuple with 1st element called class , Values of tuples 1st element (it will be 2nd element) is content ; I know this is easy question, but I'm quite new with Python as well. Thanks in any advice! 回答1:

问题 I'm wondering whether there are any good reasons to prefer a list over a tuple or vice versa in python if statments. So the following are functionally equivalent but is one preferable to the other in terms of performance and coding style or does it not matter? if x in (1,2,3): foo() if x in [1,2,3]: foo() I seem to have gotten into the habit of using tuples if there are 2 or 3 values and lists for anything longer, I think because in my experience tuples tend to be short and lists long, but