Write a function nested_double(nested_list)

Question

Exercise 7-2

Write a function nested_double(nested_list) that takes in a list of lists of integers, and returns the list with every integer doubled. You can choose to either create a new list or alter the original.

Submit your code to gradescope in a file called ex7-2.py.

Examples:

>>> nested_double([[0, 3], [], [2, 5, -10], [-9, 13, 12, 2]])

[[0, 6], [], [4, 10, -20], [-18, 26, 24, 4]]

>>> nested_double([])

[]

>>> nested_double([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

[[2, 4, 6], [8, 10, 12], [14, 16, 18]]

Answer 1

Here's the Python code for the nested_double function that takes a list of lists of integers, and returns a new list with every integer doubled:

def nested_double(nested_list):

"""

Takes a list of lists of integers, and returns a new list with every integer doubled.

"""

new_list = []

for sub_list in nested_list:

new_sub_list = []

for num in sub_list:

new_sub_list.append(num*2)

new_list.append(new_sub_list)

return new_list

Alternatively, if you want to alter the original list and not create a new list, you can modify the function to update the original list instead of creating a new one:

def nested_double(nested_list):

"""

Takes a list of lists of integers, and doubles every integer in the list.

"""for sub_list in nested_list:

for i, num in enumerate(sub_list):

sub_list[i] = num*2

With this second implementation, you don't need to return anything, because the original list will have been updated.