How to Clone or Copy Python List? (6 Methods)

Using assignment operator, we can not have two different list because both list variables point same memory location. For your verification see example below:

first_list = [1, 2, 3, 4, 5]
second_list = first_list
print("First list address: ", id(first_list))
print("Second list address: ", id(second_list))

Output

First list address:  1942422416840
Second list address:  1942422416840

Here memory address of first_list and second_list are same so they are refering the same list object [1, 2, 3, 4, 5]

To actually copy or clone list in Python, we have following methods:

1. Using List Copy Method

We can use copy() method available in list to clone a list. See example below:

original_list = [1, 2, 3, 4, 5]

# copy
copied_list = original_list.copy()

print("Original list: ", original_list)
print("Copied list: ", copied_list)
print("Original list address: ", id(original_list))
print("Copied list address: ", id(copied_list))

Output

Original list:  [1, 2, 3, 4, 5]
Copied list:  [1, 2, 3, 4, 5]
Original list address:  1942422549128
Copied list address:  1942422549000

2. Using Slice Notation

This works because slices of Python lists create new objects in memory. See example below:

original_list = [1, 2, 3, 4, 5]

# copy
copied_list = original_list[:]

print("Original list: ", original_list)
print("Copied list: ", copied_list)
print("Original list address: ", id(original_list))
print("Copied list address: ", id(copied_list))

Output

Original list:  [1, 2, 3, 4, 5]
Copied list:  [1, 2, 3, 4, 5]
Original list address:  1942422523720
Copied list address:  1942422549256

3. Using Built-in list() Function

We can use built-in list() function to create new copy of list. See example below:

original_list = [1, 2, 3, 4, 5]

# copy
copied_list = list(original_list)

print("Original list: ", original_list)
print("Copied list: ", copied_list)
print("Original list address: ", id(original_list))
print("Copied list address: ", id(copied_list))

Output

Original list:  [1, 2, 3, 4, 5]
Copied list:  [1, 2, 3, 4, 5]
Original list address:  1942422490696
Copied list address:  1942422748040

4. Using Generic copy() method from copy Module

We can use copy() method from copy module to make a brand new copy of list as:

from copy import copy

original_list = [1, 2, 3, 4, 5]

# copy
copied_list = copy(original_list)

print("Original list: ", original_list)
print("Copied list: ", copied_list)
print("Original list address: ", id(original_list))
print("Copied list address: ", id(copied_list))

Output

Original list:  [1, 2, 3, 4, 5]
Copied list:  [1, 2, 3, 4, 5]
Original list address:  1942422520328
Copied list address:  1942422488392

5. Using Generic deepcopy() from copy Module

If the list contains objects and you want to copy these object as well then you can use generic deepcopy() method from copy module. See example below:

from copy import deepcopy

original_list = [1, 2, 3, 4, 5]

# copy
copied_list = deepcopy(original_list)

print("Original list: ", original_list)
print("Copied list: ", copied_list)
print("Original list address: ", id(original_list))
print("Copied list address: ", id(copied_list))

Output

Original list:  [1, 2, 3, 4, 5]
Copied list:  [1, 2, 3, 4, 5]
Original list address:  1942422490504
Copied list address:  1942422489608

6. Using [ ] and *

You can make copy of new list using [ ] and * operators. This is same as making copy using list() method. See example below:

from copy import deepcopy

original_list = [1, 2, 3, 4, 5]

# copy
copied_list = [*original_list]

print("Original list: ", original_list)
print("Copied list: ", copied_list)
print("Original list address: ", id(original_list))
print("Copied list address: ", id(copied_list))

Output

Original list:  [1, 2, 3, 4, 5]
Copied list:  [1, 2, 3, 4, 5]
Original list address:  1942422488840
Copied list address:  1942422488712