This is the assignment: Use your knowledge of unpacking and identity to complete the function swap_lists. This function should take two lists as arguments and swap their values.
Your starter code calls your function like this: list_one = [1, 2, 3] list_two = [4, 5, 6] print "Before swap" print "list_one: " + str(list_one) print "list_two: " + str(list_two) swap_lists(list_one, list_two) print "After swap" print "list_one: " + str(list_one) print "list_two: " + str(list_two)
Note that the starter code will not run, since the function definition is empty! Hint: It won’t work to just do something like this: first, second = second, first You will instead need to use a control structure to swap individual elements in the lists!
This is my code: # swap_lists # ----- # This function takes two lists of equal length # as arguments and swaps their values. def swap_lists(first, second): if len(first) != len(second): print "Lengths must be equal!" return
# Write your code here... for i in range(3): second[i] for i in range(3): first[i]= second[i]
list_one = [1, 2, 3]
list_two = [4, 5, 6]
print "Before swap"
print "list_one: " + str(list_one)
print "list_two: " + str(list_two)
swap_lists(list_one, list_two)
print "After swap"
print "list_one: " + str(list_one)
print "list_two: " + str(list_two)What do I need to add for this to work?
2 Answers
after # write your code:
elif len(first)==len(second): for i in range(len(first)): first[i], second[i] = second[i], first[i]
def swap_lists(first, second): f = [second, first] print("After swap") print("list_one: " + str(f[0])) print("list_two: " + str(f[1])) list_one = [1, 2, 3] list_two = [4, 5, 6] print("Before swap") print("list_one: " + str(list_one)) print("list_two: " + str(list_two)) swap_lists(list_one, list_two)
