Answers for "copy and deepcopy in python"

python clone object

import copy

new_ob = copy.deepcopy(old_ob)

python deepcopy

>>> 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]}

Python Deep Copy

import copy

l1=[1,3,[9,4],6,8]
l2=copy.deepcopy(l1) #Making a deep copy

print('List 1 = ', l1)
print('List 2 = ', l2)

print('Performing change in list 2')
l2[2][0] = 5

print('List 1 = ',l1)
print('List 2 = ',l2)

python deep copy

# explaining why we need deepcopy
x = [0,1]
y = x
x.append(2)
print(x)
print(y)
# result: [0, 1, 2]
# result: [0, 1, 2]

import copy

some_list = [[0, 0, 0], [1, 1, 1], [2, 2, 2]]
other_list = copy.copy(some_list)
some_list.append([3, 3, 3])
print(some_list)
print(other_list)
# result: [0, 0, 0], [1, 1, 1], [2, 2, 2], [3, 3, 3]]
# result: [0, 0, 0], [1, 1, 1], [2, 2, 2]]

del some_list[2]
some_list[1][0] = 'One'
print(some_list)
print(other_list)
# result: [0, 0, 0], ['One', 1, 1], [2, 2, 2]]
# result: [0, 0, 0], ['One', 1, 1], [2, 2, 2]]

#this problem doesn't happen with copy.deepcopy()