set

问题 In the What’s New in Python 2.7 document it says that support for set literals was back-ported from Python 3.1. However it appears that this support was not extended to the ast module's literal_eval() function, as illustrated below. Was this intentional, an oversight, or something else -- and what are the cleanest workarounds for creating a literal set from a string representation? (I assume the following works in Python 3.1+, right?) import ast a_set = {1,2,3,4,5} print a_set print ast

问题 I'm new to PHP, and I can't figure out this basic question. Does PHP have some sort of set or list object? Something like an array, but with the ability to dynamically add or remove any number of objects from it. 回答1: Yes, you could use the array object and the array functions. Basically, you could dynamically grow an array using the array_push function, or the $arrayName[] = ... notation (where arrayName is the name of your array). 回答2: Since you've mentioned a "Set object" in the question's

问题 Ok, here's my situation: I have an Array of States, which may contain duplicates. To get rid of the duplicates, I can add them all to a Set. However when I create the Set, it wants the initial capacity and load factor to be defined, but what should they be set to? From googling, I have come up with: String[] allStates = getAllStates(); Set<String> uniqueStates = new HashSet<String>(allStates.length, 0.75); The problem with this, is that allStates can contain anwhere between 1 and 5000 states.

问题 Ok, here's my situation: I have an Array of States, which may contain duplicates. To get rid of the duplicates, I can add them all to a Set. However when I create the Set, it wants the initial capacity and load factor to be defined, but what should they be set to? From googling, I have come up with: String[] allStates = getAllStates(); Set<String> uniqueStates = new HashSet<String>(allStates.length, 0.75); The problem with this, is that allStates can contain anwhere between 1 and 5000 states.

问题 I have a class with an enum property like so: public class Foo { public Color ColorType {get;set;} } public enum Color { Red, Green, } Now this class can be initialized like so: var foo = new Foo(); without the ColorType property ever being set. Now, I'm trying to create a method and perform actions on whether that enum was ever set or not, for example I have a method private void checkEnum(Foo foo) { if(foo.ColorType !=null) { //perform these actions }else { //perform those actions } }

问题 I am working on a c++ program with a set of sets. Here is the declared set of sets. std::set< std::set<int> > temp_moves; I am getting the error below in this declaration, my question is that is my syntax correct? is it possible to create a set of sets in programs? error: no matching function for call to ‘std::set<std::set<int> >::insert(int&)’ Updated Code std::set<int> next_moves; std::set<int> available_numbers; for (const auto available_number : available_numbers) temp_moves.insert(number

问题 i got some issues trying to convert my map into a set I got a "Chanson" object with this member data : std::map<std::string,Artiste*> m_interpretes; Here is how i add my *Artiste to my map : void Chanson::addArtiste(Artiste* a) throw (ExceptionArtiste, ExceptionLangueIncompatible) { if(a!=NULL) { if(a->getLangue() == this->getLangue()) { m_interpretes.insert(pair<string, Artiste*>(a->getNom(), a)); //m_interpretes[a->getNom()] = a; } else { throw ExceptionLangueIncompatible(a,this); } } } set

问题 I want to operate on abstract sets. But it dosen't work. from pyomo.environ import * m = AbstractModel() m.A = Set(initialize=[0,1,2]) m.B = Set(initialize=[0]) m.C = m.A-m.B instance = m.create_instance() for c in instance.C.value: print(c) TypeError: 'NoneType' object is not iterable 回答1: Based on what you told to Qi Chen, here is a working example of your code if you used the AbstractModel formulation. The thing, with abstract models, is that it doesn't do much more than delay the

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 2 years ago . I had a loop of the form for thing in a_set: . It was working incorrectly because, occasionally and inconsistently, it would pull the same thing from the set twice. (This does not cause the program to crash. It just gets the wrong answer.) I was not able to determine anything that was deterministic about the

问题 Greetings, what I'm trying to do is to port an existing Windows application to Linux using CMake with CMakeLists, which I generated with the vcproj2cmake Script (https://github.com/sixman9/vcproj2cmake). With the CMakeLists.txt and CMake I was able to successfully port a VS 2005 project to VS 2010. Now I try to port the same VS 2005 project to Linux, so that I can edit it with KDevelope. The project itself is small and I think it would be easier to just create a new project and copy all