Python list copy() method “returns a shallow copy of the list”.
Syntax
newList = list.copy()
Parameters
It does not take any arguments.
Return value
The copy() method returns a new list. It doesn’t modify the original list.
You have to provide the source list to copy the elements of that list.
Example 1: How to Copy a List
targaryens = ['Aegon', 'Daenerys', 'Aemon', 'Aeris', 'Rhaegar', 'Viserys']
clonedList = targaryens.copy()
print(clonedList)Output
The copy() function returns a list. However, it doesn’t modify the original list.
Example 2: Copying and modifying a list
targaryens = ['Aegon', 'Daenerys', 'Aemon', 'Aeris', 'Rhaegar', 'Viserys']
clonedList = targaryens.copy()
print(clonedList)
print(targaryens)
targaryens.append('Daemon')
print('---After modified---')
print(targaryens)
print(clonedList)
Output
Example 3: Copy List Using Slicing Syntax
Python slice() method is considered when we want to modify the list and also keep the copy of an original.
In this scenario, we copy the list and the reference. This process is also called cloning. The technique takes about 0.039 seconds and is the fastest technique.
targaryens = ['Aegon', 'Daenerys', 'Aemon', 'Aeris', 'Rhaegar', 'Viserys']
sliceCopy = targaryens[:]
print(sliceCopy)
Output
Copy a list using =
You can use the “=” operator to copy the list. The only drawback to this method is that it does not create a shallow copy.
list = [11, 21, 19]
list_new = list
print("This is the new list: " + str(list_new))
list_new.append(46)
print("The new list after adding a new element: " + str(list_new))
print("The old list after adding a new element" + str(list))
Output
This is the new list: [11, 21, 19]
The new list after adding a new element: [11, 21, 19, 46]
The old list after adding a new element: [11, 21, 19, 46]
That’s it.
Krunal Lathiya is a seasoned Computer Science expert with over eight years in the tech industry. He boasts deep knowledge in Data Science and Machine Learning. Versed in Python, JavaScript, PHP, R, and Golang. Skilled in frameworks like Angular and React and platforms such as Node.js. His expertise spans both front-end and back-end development. His proficiency in the Python language stands as a testament to his versatility and commitment to the craft.
