Question

1. Make a function make_list_of_lists(n, m) that creates and returns a list of n lists of size m, where each of the m elements in a sublist are randomly generated integers between 1 and 9. For example, you might obtain

l = make_list_of_lists(2,2)
>>> print(l)
[[1, 4], [5, 7]]

Big Hint: You can do this using numpy along the lines of the following code:

import numpy
>>> l = list(numpy.random.randint(a,b,c))

where you need to sort out what the values of a, b and c do to create the list you want.

2. Once you have this function working, generate a second function called deep_copy_list_of_lists that makes a genuine copy of an input list, i.e., it does not alias the list or its elements. Use only the tools we have learned in lecture to do this.

3. Prove that your deep copy function works by using your list generating function to create a random list of lists with three (3) lists with five (5) elements (n = 3, m = 5), using your deep copy function to copy it (preserving the original list), and then changing some of the numbers in the copied list by indexing each number directly, showing that the original list has not changed. Print the output of each of these operations and include this output as a comment in your submission. Do NOT query the user for input.

Answer 1

# do comment if any problem arises
# Code
import numpy

def make_list_of_lists(n, m):
# create list using numpy
l = list(numpy.random.randint(low=1,high=10,size=[n, m]))
return l

def deep_copy_list_of_lists(l):
# create a copy of given list
copy=[[0]*len(l[0]) for i in range(len(l))]
for i in range(len(l)):
for j in range(len(l[0])):
copy[i][j]=l[i][j]
return copy
  
# this function prints given list
def print_list(l):
for i in range(len(l)):
for j in range(len(l[0])):
print(l[i][j],end=" ")
print()
  
# testing above function
l=make_list_of_lists(3, 5)
# creating copy
copy=deep_copy_list_of_lists(l)
print("Changing first element of original list")
l[0][0]=22
print("\nCopy: \n")
print_list(copy)
print("\nOriginal: \n")
print_list(l)

Screenshot:

Output: