Madhavan Mukund

Assignment 3

14 October, 2024, due 24 October 2024

User defined lists

List.py contains the user defined List class that we discussed in Lectures 13 and 14.

Modify this class to add the following functionality:

1. Write a function member() such that l.member(v) returns True if the value v is present in list l and False otherwise.

2. Write a function valueat() such that l.valueat(i) returns the value at index i. This is equivalent to l[i] for normal Python lists. As usual, valid indices run from 0 to length(l) - 1.

   • The function should raise an IndexError if the index is not valid. The error message should include the index requested.

3. Modify the function insert() so that, for a List l, l.insert(v,i) inserts v before index i. In other words, after the insert, l.valueat(i) should be v. The index i is valid if it lies in the range 0 to length(l). When i is length(l), the effect is the same as l.append(v).

   • The default value for the index i is 0. So, l.insert(v) should behave like l.insert(v,0).

   • The function should raise an IndexError if the index is not valid. The error message should include the index requested.

4. Write a function deleteall() such that l.deleteall(v) deletes all occurrences of the value v from the list l.

   • The function should raise a ValueError if the value to be deleted is not present in the list. The error message should include the value to be deleted.

5. Write a function slice() such that l.slice(i,j) returns a new list containing the slice from l.valueat(i) to l.valueat(j-1).

   This is equivalent to l[i:j] for normal Python lists. The function slice() always takes two arguments. However, follow the usual list slicing conventions in case i < 0, j ≤ i or j ≥ length(l). Do not generate any errors or raise any exceptions.

6. Write a function reverse() such that l.reverse() reverses the list in place.