deep-copy | 易学教程

Create a Deep Copy in C#

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问题 I want to make a deep copy of an object so I could change the the new copy and still have the option to cancel my changes and get back the original object. My problem here is that the object can be of any type, even from an unknown assembly. I can not use BinaryFormatter or XmlSerializer , because the object unnecessarily have [Serializable] attribute. I have tried to do this using the Object.MemberwiseClone() method: public object DeepCopy(object obj) { var memberwiseClone = typeof(object)

Deep copy of List<T>

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I'm trying to make a deep copy of a generic list, and am wondering if there is any other way then creating the copying method and actually copying over each member one at a time. I have a class that looks somewhat like this: public class Data { private string comment; public string Comment { get { return comment; } set { comment = value; } } private List<double> traceData; public List<double> TraceData { get { return traceData; } set { traceData = value; } } } And I have a list of the above data, i.e List<Data> . What I'm trying to do is plot a trace data of the subset of List onto a graph,

Deep copying a PSObject

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问题 I have a powershell script in which I do the following $somePSObjectHashtables = New-Object Hashtable[] $somePSObject.Length; $somePSObjects = Import-CSV $csvPath 0..($somePSObject.Length - 1) | ForEach-Object { $i = $_; $somePSObjectHashtables[$i] = @{}; $somePSObject[$_].PSObject.Properties | ForEach-Object { $somePSObjectHashtables[$i][$_.Name] = $_.Value; } } I need to do this because I want to make several distinct copies of the data in the CSV to perform several distinct manipulations.

How can I make a deepcopy of a function in Python?

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问题 I would like to make a deepcopy of a function in Python. The copy module is not helpful, according to the documentation, which says: This module does not copy types like module, method, stack trace, stack frame, file, socket, window, array, or any similar types. It does “copy” functions and classes (shallow and deeply), by returning the original object unchanged; this is compatible with the way these are treated by the pickle module. My goal is to have two functions with the same

How to create a deep copy of an object in Ruby?

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I did some searching found some different methods and posts about creating a deep copy operator. Is there a quick and easy (built-in) way to deep copy objects in Ruby? The fields are not arrays or hashes. Working in Ruby 1.9.2. Deep copy isn't built into vanilla Ruby, but you can hack it by marshalling and unmarshalling the object: Marshal.load(Marshal.dump(@object)) This isn't perfect though, and won't work for all objects. A more robust method: class Object def deep_clone return @deep_cloning_obj if @deep_cloning @deep_cloning_obj = clone @deep_cloning_obj.instance_variables.each do |var|

python Pandas DataFrame copy(deep=False) vs copy(deep=True) vs '='

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问题 Could somebody explain to me a difference between df2 = df1 df2 = df1.copy() df3 = df1.copy(deep=False) I have tried all options and did as follows: df1 = pd.DataFrame([1,2,3,4,5]) df2 = df1 df3 = df1.copy() df4 = df1.copy(deep=False) df1 = pd.DataFrame([9,9,9]) and returned as follows: df1: [9,9,9] df2: [1,2,3,4,5] df3: [1,2,3,4,5] df4: [1,2,3,4,5] So, I observe no difference in the output between .copy() and .copy(deep=False) . Why? I would expect one of the options \'=\', copy(), copy(deep

Does a slicing operation give me a deep or shallow copy?

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问题 The official Python docs say that using the slicing operator and assigning in Python makes a shallow copy of the sliced list. But when I write code for example: o = [1, 2, 4, 5] p = o[:] And when I write: id(o) id(p) I get different id\'s and also appending one one list does not reflect in the other list. Isn\'t it creating a deep copy or is there somewhere I am going wrong? 回答1: You are creating a shallow copy, because nested values are not copied, merely referenced. A deep copy would create

Shallow copy or Deep copy?

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问题 I am a bit new to these two methods of copying one object into the other. I am confused and unable to spot out the major difference between deep copy and shallow copy.. I had gone through a lots of theory regarding this, but I need explanation with proper examples.. I have program in which I copy one object into another. --> class A { public int a = 0; public void display() { Console.WriteLine(\"The value of a is \" + a); } } class Program { static void Main(string[] args) { A ob1 = new A();

Deep copy of dictionaries gives Analyze error in Xcode 4.2

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问题 I have the following method in a NSDictionary category, to do a deep copy, which works fine. I just upgraded from Xcode 4.1 to 4.2, and the Analyze function gives two analyzer warnings for this code, as indicated: - (id)deepCopy; { id dict = [[NSMutableDictionary alloc] init]; id copy; for (id key in self) { id object = [self objectForKey:key]; if ([object respondsToSelector:@selector(deepCopy)]) copy = [object deepCopy]; else copy = [object copy]; [dict setObject:copy forKey:key]; // Both

Deep copying an NSArray

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Is there any built-in function that allows me to deep copy an NSMutableArray ? I looked around, some people say [aMutableArray copyWithZone:nil] works as deep copy. But I tried and it seems to be a shallow copy. Right now I am manually doing the copy with a for loop: //deep copy a 9*9 mutable array to a passed-in reference array -deepMuCopy : (NSMutableArray*) array toNewArray : (NSMutableArray*) arrayNew { [arrayNew removeAllObjects];//ensure it's clean for (int y = 0; y<9; y++) { [arrayNew addObject:[NSMutableArray new]]; for (int x = 0; x<9; x++) { [[arrayNew objectAtIndex:y] addObject: