Question

Consider the following lines of Python code.
x = [423,'b',37,'f']
u = x[1:]
y = u
w = x
u = u[0:]
u[1] = 53
x[2] = 47
After these execute, which of the following is correct?
x[2] == 47, y[1] == 37, w[2] == 47, u[1] == 53
x[2] == 47, y[1] == 53, w[2] == 47, u[1] == 53
x[2] == 47, y[1] == 37, w[2] == 37, u[1] == 53
x[2] == 47, y[1] == 53, w[2] == 37, u[1] == 53

Answer 1

Answer:

x[2] == 47, y[1] == 37, w[2] == 47, u[1] == 53

Explanation:

Answer 2

The correct option is x[2] == 47, y[1] == 37, w[2] == 47, u[1] == 53

Explanation

Let's go step by step to understand what is happening in the Python códe

x = [423, 'b', 37, 'f']

A list 'x' is defined which having some values.

u = x[1:]

In this 'x' list is getting sliced with the last three value and stored in variable 'u' which means

u = ['b', 37, 'f']

y = u

In variable 'y' value of variable 'u' is assigned.

y =  ['b', 37, 'f']

w = x

In variable 'w' value of variable 'x' is assigned.

y = [423, 'b', 37, 'f']

u = u[0:]

In this 'u' list is getting sliced with no value so, it will still be

u = ['b', 37, 'f']

u[1] = 53

In this 'u' list u[1] is getting assigned with value 53 which will update the 'u' list as follows

u = ['b', 53, 'f']

x[2] = 47

In this 'x' list x[2] is getting assigned with value 47 which will update the 'x' list as follows

x = [423, 'b', 47, 'f']

Extra Information

Colon Operator (:)

Colon operator helps us in slicing a part of a list, tuple, or string.

Format of Colon operator

[startingIndex : endingIndex]

Both of these parameters that are startingIndex and endingIndex are optional.

If startingIndex is not mentioned then it will consider 0 as startingIndex.

If endingIndex is not mentioned then it will consider the last index of the list, tuple, or string.

Example

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

print(a[1:3])

[2, 3]

print(a[:3])

[1, 2, 3]

print(a[2:])

[3, 4, 5]

Python is created by Guido van Rossum and came into existence in 1991. It is a high-level and general programming language. It is a very lucid programming language as it has a good language construct and object-oriented approach. It is dynamically typed and garbage-collected.