debugging a simple code.

[v13tn1g]

I have a function that won't work is it possible for someone to debug it for me?...i've been trying to play with everything...

def reverse(L):
    """Given a list, return a new list that is the same as the original list except that its members are in reverse order, without changing the original.""" 
    M=list()
    for i in L:
        M.append(L[i])
        M.reverse()
    return M

[boxfish]

These lines are the problem:

for i in L:
    M.append(L[i])

i contains items from the list, not list indices. The code should be

for i in L:
    M.append(i)

However, a more compact way to copy a list is with a slice:

M = L[:]

I hope this is helpful.

[bvdet]

To give you some alternatives, you can create a reversed list using the slice operator and the range function in a list comprehension. You could also use a for loop in combination with range() instead of the comprehension.

>>> aList = [0,1,2,3,4,5,6,7,8,9]
>>> anotherList = aList[::-1]
>>> aList
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>>> anotherList
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
>>> anotherList2 = [aList[i] for i in range(len(aList)-1, -1, -1)]
>>> anotherList2
[9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
>>>