copy() method creates a new reference variable to the original data whereas deepcopy dont reflect the change after modification of the original data

>>> import copy

>>> nums = [1, 2, 3]

>>> data = {'a': 10, 'b': nums}

>>> data

{'a': 10, 'b': [1, 2, 3]}

>>> data_copy = copy.copy(data)

>>> data_deep = copy.deepcopy(data)

>>> data_copy

{'a': 10, 'b': [1, 2, 3]}

>>> data_deep

{'a': 10, 'b': [1, 2, 3]}

>>> data_copy['a'] += 2

>>> nums[1:1] = [254]

>>> data

{'a': 10, 'b': [1, 254, 2, 3]}

>>> data_copy

{'a': 12, 'b': [1, 254, 2, 3]}

>>> data_deep

{'a': 10, 'b': [1, 2, 3]}