deep-copy

I wanted to ask that how will we implement a copy constructor of a class which has self pointer to itself as its data member, i want to implement a deep copy, class City { string name; City* parent; public: City(string nam, double dcov); City(string nam, double dcov, City* c); City(const City& obj) { this-> name = obj.name; // how to assign parent parent = new City(??) } ~City(); void setName(string name1); void setDistanceCovered(int dist); string getName(); double getDistanceCovered(); City* getParent(){return parent;} }; I am confused that this line // how to assign parent parent = new City

def dropdf_copy(df): df = df.drop('y',axis=1) def dropdf_inplace(df): df.drop('y',axis=1,inplace=True) def changecell(df): df['y'][0] = 99 x = pd.DataFrame({'x': [1,2],'y': [20,31]}) x Out[204]: x y 0 1 20 1 2 31 dropdf_copy(x) x Out[206]: x y 0 1 20 1 2 31 changecell(x) x Out[208]: x y 0 1 99 1 2 31 In the above example dropdf() doesnt modify the original dataframe x while changecell() modifies x. I know if I add the minor change to changecell() it wont change x. def changecell(df): df = df.copy() df['y'][0] = 99 I dont think its very elegant to inlcude df = df.copy() in every function I

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . I was using a custom method to deep clone objects the other day, and I know you can deep clone in different ways (reflection, binary serialization, etc), so I was just wondering: What is/are the reason(s) that Microsoft does not include

Consider the following class: class A { char *p; int a, b, c, d; public: A(const &A); }; Note that I have to define a copy constructor in order to do a deep copy of "p". This has two issues: Most of the fields should simply be copied. Copying them one by one is ugly and error prone. More importantly, whenever a new attribute is added to the class, the copy constructor needs to be updated, which creates a maintenance nightmare. I would personally like to do something like: A(const A &a) : A(a) { // do deep copy of p ::: } So the default copy constructor is called first and then the deep copy is

Suppose I have the following (simplified case): class Color; class IColor { public: virtual Color getValue(const float u, const float v) const = 0; }; class Color : public IColor { public: float r,g,b; Color(float ar, float ag, float ab) : r(ar), g(ag), b(ab) {} Color getValue(const float u, const float v) const { return Color(r, g, b) } } class Material { private: IColor* _color; public: Material(); Material(const Material& m); } Now, is there any way for me to do a deep copy of the abstract IColor in the copy constructor of Material? That is, I want the values of whatever m._color might be

a linear linked list is a set of nodes. This is how a node is defined (to keep it easy we do not distinguish between node an list): class Node{ Object data; Node link; public Node(Object pData, Node pLink){ this.data = pData; this.link = pLink; } public String toString(){ if(this.link != null){ return this.data.toString() + this.link.toString(); }else{ return this.data.toString() ; } } public void inc(){ this.data = new Integer((Integer)this.data + 1); } public void lappend(Node list){ Node child = this.link; while(child != null){ child = child.link; } child.link = list; } public Node copy(){