Python – Copy Lists

Copy a List

You cannot copy a list simply by typing list2 =
list1, because: list2 will only be a reference to list1, and changes made in list1 will automatically also be made in list2.

Use the copy() method

You can use the built-in List method copy() to copy a list.

Example

Make a copy of a list with the copy() method:

thislist = ["apple", "banana", "cherry"]
mylist = thislist.copy()
print(mylist)

Use the list() method

Another way to make a copy is to use the built-in method list().

Example

Make a copy of a list with the list() method:

thislist = ["apple", "banana", "cherry"]
mylist = list(thislist)
print(mylist)

Use the slice Operator

You can also make a copy of a list by using the : (slice) operator.

Example

Make a copy of a list with the : operator:

thislist = ["apple", "banana", "cherry"]
mylist = thislist[:]
print(mylist)