How to copy a Python class instance if deepcopy() does not work?
Yes you can make a copy of class instance using deepcopy: from copy import deepcopy c = C(4,5,’r’=2) d = deepcopy(c) This creates the copy of class instance ‘c’ in ‘d’ .
deep-copy
How can I make a deepcopy of a function in Python?
The FunctionType constructor is used to make a deep copy of a function. import types def copy_func(f, name=None): return types.FunctionType(f.func_code, f.func_globals, name or f.func_name, f.func_defaults, f.func_closure) def A(): “””A””” pass B = copy_func(A, “B”) B.__doc__ = “””B”””
How to deep copy a Hibernate entity while using a newly generated entity identifier
Just retrieve the object, detach it, set the id to null and persist it. MyEntity clone = entityManager.find(MyEntity.class, ID); entityManager.detach(clone); clone.setId(null); entityManager.persist(clone); If your object have oneToMany relationships, you will have to repeat the operation for all the children but setting your parent object id (generated after the persist call) instead of null. Of course … Read more
Shallow copy or Deep copy?
From the link here Shallow copies duplicate as little as possible. A shallow copy of a collection is a copy of the collection structure, not the elements. With a shallow copy, two collections now share the individual elements. Deep copies duplicate everything. A deep copy of a collection is two collections with all of the … Read more
How to copy a “Dictionary” in Swift?
A ‘Dictionary’ is actually a Struct in swift, which is a value type. So copying it is as easy as: let myDictionary = … let copyOfMyDictionary = myDictionary To copy an object (which is a reference type) has a couple of different answers. If the object adopts the NSCopying protocol, then you can just do: … Read more
deep extend (like jQuery’s) for nodeJS
It’s already been ported. node-extend Note the project doesn’t have tests and doesn’t have much popularity, so use at your own risk. As mentioned you probably don’t need deep copies. Try to change your data structures so you only need shallow copies. Few months later I wrote a smaller module instead, recommend you use xtend. … Read more
python Pandas DataFrame copy(deep=False) vs copy(deep=True) vs ‘=’
If you see the object IDs of the various DataFrames you create, you can clearly see what is happening. When you write df2 = df1, you are creating a variable named df2, and binding it with an object with id 4541269200. When you write df1 = pd.DataFrame([9,9,9]), you are creating a new object with id … Read more
deepcopy() is extremely slow
Actually, deepcopy is very slow. But we can use json, ujson, or cPickle. we can use json/cPickle to dump an object, and load it later. This is my test: Total time: 3.46068 s File: test_deepcopy.py Function: test at line 15 Line # Hits Time Per Hit % Time Line Contents ============================================================== 15 @profile 16 def … Read more
How to create a deep copy of an object in Ruby?
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| val = @deep_cloning_obj.instance_variable_get(var) begin @deep_cloning = true val … Read more
Does Object.assign() create a deep copy or a shallow copy?
Forget about deep copy, even shallow copy isn’t safe, if the object you’re copying has a property with enumerable attribute set to false. MDN : The Object.assign() method only copies enumerable and own properties from a source object to a target object take this example var o = {}; Object.defineProperty(o,’x’,{enumerable: false,value : 15}); var ob={}; … Read more