[Python] Does Python make a copy of objects on assignment?

When I try this code:

dict_a = dict_b = dict_c = {}
dict_c['hello'] = 'goodbye'

print(dict_a)
print(dict_b)
print(dict_c)


I expected that it would just initialise the dict_a, dict_b and dict_c dictionaries, and then assign a key in dict_c, resulting in

{}
{}
{'hello': 'goodbye'}


But it seems to have a copy-through effect instead:

{'hello': 'goodbye'}
{'hello': 'goodbye'}
{'hello': 'goodbye'}


Why?


See also:

• How do I clone a list so that it doesn't change unexpectedly after assignment?
• What is the difference between shallow copy, deepcopy and normal assignment operation?

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