deep-copy

问题 How to Clone or Serialize a Windows Forms Control? When I am trying to Clone windows forms controls using this code "CloneControl(Control ct1)", it allows me to duplicate controls with some Serializable properties, not with all properties. public Form1() { InitializeComponent(); Columns = new DataGridViewTextBoxColumn[2]; for (int i = 0; i < 2; i++) { Columns[i] = new System.Windows.Forms.DataGridViewTextBoxColumn(); // // Columns[i] // Columns[i].HeaderText = "j" + (i + 1); Columns[i].Name =

问题 I am dealing with some classes using pygraph module and when I use add_node() method, it always comes out 'node xxx already in graph'. So I try to use deepcopy() to create a new instance and have some problem with it: class test: _storage = [] def add_item(self,item): self._storage.append(item) def pop_item(self,item): return self._storage.pop() def __repr__(self): return '%s' %self._storage[:] if __name__ == '__main__': a1 = test() a1.add_item(3) a1.add_item(4) from copy import copy,deepcopy

问题 I've been playing with Cython recently for the speed ups, but when I was trying to use copy.deepcopy() some error occurred.Here is the code: from copy import deepcopy cdef class cy_child: cdef public: int move[2] int Q int N def __init__(self, move): self.move = move self.Q = 0 self.N = 0 a = cy_child((1,2)) b = deepcopy(a) This is the error: can't pickle _cython_magic_001970156a2636e3189b2b84ebe80443.cy_child objects How can I solve the problem for this code? 回答1: As hpaulj says in the

问题 How is Deep copy being done in python for lists? I am a little confused for copying of lists. Is it using shallow copy or deep copy? Also, what is the syntax for sublists? is it g=a[:] ? 回答1: The new list is a copy of references. g[0] and a[0] both reference the same object. Thus this is a shallow copy. You can see the copy module's deepcopy method for recursively copying containers, but this isn't a common operation in my experience. Stylistically, I prefer the more explicit g = list(a) to

问题 I'm trying to copy sf::RenderTexture (with sf::Image & sf::Text on it), to Opencv Mat object. We can convert an sf::Image to cv::Mat (Opencv) by sf::Image img; cv::Size size(img.getSize().x, img.getSize().y); cv::Mat mat(size,CV_8UC4, (void*)img.getPixelsPtr(), cv::Mat::AUTO_STEP); cv::cvtColor(mat, mat, cv::COLOR_RGBA2BGRA); as far as I know, in SFML we cannot add text directly to sf::Image but we have to use RenderWindow or RenderTexture for that. I guess only workaround is to load objects

问题 I know you can give a list object as parameter of list constructor to copy 1 list to the other. By doing so, you can create a deep copy if used types are simple build-in once ( which precisely? ). For example of type string : List<string> testList = new List<string>(); List<string> testListCopy = new List<string>(testList ); Can you create a deep copy if you work with nested Lists? : List<List<string>> testList = new List<List<string>>(); List<List<string>> testListCopy = new List<List<string

问题 Suppose i have a python list l consisting of immutables. When i am doing a shallow copy and a deep copy , the result is same: >>> a = (1,2) # immutable types >>> b = (3,4) >>> l = [a,b] # a list containing immutable types >>> import copy >>> y = copy.copy(l) # shallow copy >>> z = copy.deepcopy(l) # deep copy >>> id(l[0]) 139857440375584 >>> id(y[0]) 139857440375584 >>> id(z[0]) 139857440375584 # all have the same id's , so all refer to the same object Does it means that shallow copy and deep

问题 Here's some sample scala code. abstract class A(val x: Any) { abstract def copy(): A } class b(i: Int) extends A(i) { override def copy() = new B(x) } class C(s: String) extends A(s) { override def copy() = new C(x) } //here's the tricky part Trait t1 extends A { var printCount = 0 def print = { printCount = printCount + 1 println(x) } override def copy = ??? } Trait t2 extends A { var doubleCount = 0 def doubleIt = { doubleCount = doubleCount + 1 x = x+x } override def copy = ??? } val q1 =

问题 As a Python newbie coming from the C++ background, the slicing operator in Python (3.4.x) looks ridiculous to me. I just don't get the design philosophy behind the "special rule". Let me explain why I say it's "special". On the one hand, according to the Stack Overflow answer here, the slicing operator creates a (deep) copy of a list or part of the list , i.e. a new list. The link may be old (earlier than python 3.4.x), but I just confirmed the behavior with the following simple experiment

问题 I'd like to override __deepcopy__ for a given SQLAlchemy-mapped class such that it ignores any SQLA attributes but deepcopies everything else that's part of the class. I'm not particularly familiar with overriding any of Python's built-in objects in particular but I've got some idea as to what I want. Let's just make a very simple class User that's mapped using SQLA. class User(object): def __init__(self, user_id=None, name=None): self.user_id = user_id self.name = name I've used dir() to see