List Data type- Part-3

 

Aliasing and Cloning of List objects:

Aliasing

The process of giving another reference variable to the existing list is called aliasing.

Eg:

x=[10,20,30,40]

y=x

print(id(x))

print(id(y))

 The problem in this approach is by using one reference variable if we are changing content, then those changes will be reflected to the other reference variable.

x=[10,20,30,40]

y=x

y[1]=777

print(x) ---------->[10,777,30,40]

To overcome this problem we should go for cloning.

Cloning :

The process of creating exactly duplicate independent object is called cloning.

We can implement cloning by using

•  slice operator
• or by using copy() function

1. By using slice operator:

x=[10,20,30,40]

y=x[:]

y[1]=777

print(x) ------>[10,20,30,40]

print(y) ------->[10,777,30,40]

2. By using copy() function:

x=[10,20,30,40]

y=x.copy()

y[1]=777

print(x) ----->[10,20,30,40]

print(y) ------>[10,777,30,40]

Difference between = operator and copy() function

= operator is meant for aliasing

copy() function is meant for cloning