I am asked to reverse a which takes head as parameter where as head is a linked list e.g.: 1 -> 2 -> 3 which was returned from a function already defined I tried to implement the function reverse_linked_list in this way:

def reverse_linked_list(head):
    temp = head
    head = None
    temp1 = temp.next
    temp2 = temp1.next
    temp1.next = None
    temp2.next = temp1
    temp1.next = temp
    return temp2

class Node(object):
    def __init__(self,value=None):
        self.value = value
        self.next = None

    def to_linked_list(plist):
    head = None
    prev = None
    for element in plist:
        node = Node(element)
        if not head:
            head = node
        else:
            prev.next = node
        prev = node
    return head

    def from_linked_list(head):
    result = []
    counter = 0
    while head and counter < 100: # tests don't use more than 100 nodes, so bail if you loop 100 times.
        result.append(head.value)
        head = head.next
        counter += 1
    return result

    def check_reversal(input):
        head = to_linked_list(input)
        result = reverse_linked_list(head)
        assert list(reversed(input)) == from_linked_list(result)

It is called in this way: check_reversal([1,2,3]). The function I have written for reversing the list is giving [3,2,1,2,1,2,1,2,1] and works only for a list of length 3. How can I generalize it for a list of length n?