Python Coding Challange - Question With Answer(01290125)

 

Here's an explanation of the code:

Code:

i = j = [3]
i += jprint(i, j)

Step-by-Step Explanation:

1. Assignment (i = j = [3]):

   • A single list [3] is created in memory.
   • Both i and j are assigned to reference the same list object.
   • At this point:

     
     i -> [3]
     j -> [3]

2. In-place Addition (i += j):

   • The += operator modifies the object that i refers to in place.
   • Since i and j refer to the same list object, modifying i affects j as well.
   • The list [3] is extended by adding the elements of j (which is also [3]) to it.
   • After this operation, the list becomes [3, 3].
   • Now:

     
     i -> [3, 3]
     j -> [3, 3]

3. Output (print(i, j)):

   • Both i and j refer to the same modified list [3, 3], so the output is:

     
     [3, 3] [3, 3]

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Key Concepts:

1. Shared References:

   • When you do i = j = [3], both i and j point to the same object in memory.
   • Any in-place modification to the list (like i += j) will affect both i and j.

2. In-place Operations with +=:

   • For lists, += modifies the list in place (equivalent to i.extend(j)).
   • It does not create a new object. Instead, it updates the existing object.