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*Memo:

• My post explains the shallow and deep copy of a list.
• My post explains the shallow and deep copy of a tuple.
• My post explains the shallow and deep copy of the set with an iterator.
• My post explains the shallow and deep copy of a dictionary.
• My post explains the shallow and deep copy of an iterator.
• My post explains a set and the set with copy.

<A set with a tuple>

A set can have the hashable types of elements like frozenset, tuple, iterator, etc but cannot have the unhashable types of elements like set, list, dict, etc.

*Memo:

• The same tuple is always referred to because a tuple cannot be copied according to the experiments so for the set with a tuple, only shallow copy is possible.

<Normal Copy>:

*Memo:

• A and B refer to the same shallow set and deep tuple.
• is keyword can check if v1 and v2 refer to the same set or tuple.

# Shallow set # ↓ ↓ A = {('a',)} # ↑↑↑↑↑↑ Deep tuple B = A print(A) # {('a',)} print(B) # {('a',)}  print(A is B) # True  print(A.pop()) # ('a',) print(B.pop()) # KeyError: 'pop from an empty set' 

<Shallow Copy>:

set.copy() does shallow copy as shown below:

*Memo:

• A and B refer to different shallow sets.
• A and B refer to the same deep tuple.

A = {('a',)} B = A.copy() print(A) # {('a',)} print(B) # {('a',)}  print(A is B) # False  v1 = A.pop() v2 = B.pop() print(v1) # ('a',) print(v2) # ('a',)  print(v1 is v2) # True 

The below with copy.copy() which does shallow copy is equivalent to the above:

import copy A = {('a',)} B = copy.copy(A) print(A) # {('a',)} print(B) # {('a',)}  print(A is B) # False  v1 = A.pop() v2 = B.pop() print(v1) # ('a',) print(v2) # ('a',)  print(v1 is v2) # True 

The below with set() which does shallow copy is equivalent to the above:

A = {('a',)} B = set(A) print(A) # {('a',)} print(B) # {('a',)}  print(A is B) # False  v1 = A.pop() v2 = B.pop() print(v1) # ('a',) print(v2) # ('a',)  print(v1 is v2) # True 

The below with deepcopy() which does deep copy is equivalent to the above:

*Memo:

• copy.deepcopy() should be used because it's safe, doing copy deeply while set.copy(), copy.copy() and set() aren't safe, doing copy shallowly.

import copy A = {('a',)} B = copy.deepcopy(A) print(A) # {('a',)} print(B) # {('a',)}  print(A is B) # False  v1 = A.pop() v2 = B.pop() print(v1) # ('a',) print(v2) # ('a',)  print(v1 is v2) # True 

Additionally, the below is the 3D set with a 2D tuple:

import copy A = {(('a',),)} B = copy.deepcopy(A) print(A) # {(('a',),)} print(B) # {(('a',),)}  print(A is B) # False  v1 = A.pop() v2 = B.pop() print(v1) # (('a',),) print(v2) # (('a',),)  print(v1[0]) # ('a',) print(v2[0]) # ('a',)  print(v1 is v2, v1[0] is v2[0]) # True True