kinda wish you could thumbs-down the questions that pretend to cater to some languages and just don't. I guess it's python again then...

def insertNodeAtPosition(llist, data, position):
    newNode = SinglyLinkedListNode(data)
    if position == 0:
        newNode.next = llist
        return newNode
    insertAt = llist
    while position > 1:
        position-=1
        insertAt = insertAt.next
    newNode.next = insertAt.next
    insertAt.next = newNode
    return llist