What would you expect to be the output of the following code snippet: `a = [1, 2, 3]; b = a; b[1] = 4; print(a); print(b);`, and why?

a = [1, 2, 3] b = a b[1] = 4 print(a) print(b) The output of this would be:[1, 4, 3] [1, 4, 3] This occurs because lists in Python are pass-by-reference, rather than pass-by-value. What this means is that when we assign b to a, we are not copying the list [1,2,3] to b, we are just copying the reference! So when we change the second element of b to 4, then print a and b, both of them print [1,4,3], because both of them point to the same list.

IQ
Answered by Ibrahim Q. Python tutor

2630 Views

See similar Python Mentoring tutors

Related Python Mentoring answers

All answers ▸

Demonstrate a recursive solution to calculate the factorial of a number


Create a python code to sum the number from 1 to 10.


Why are negative indexes used?


Implement a rocket launch countdown.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences