node swap for doubly linked list python

Still working on my quick sort.
I think I got this all shiny.  Will be going to the Doubly Linked List post to add it in.

It will swap left or right.  end or begin.  I've been using it on large randomly generated lists without a problem.  Well, without a problem NOW.

I had so many gremlins pop up making this thing work...
The order in which the links are set are soooo touchy..... bull in a china shop.
Throw a match into the oxygen chamber and everything goes to hell.

Anyhoo.   Here it is.
If anyone happens to spot anymore of those little bastards that threw all the monkey wrenches at me, feel free to point them out.  I'd love to get my hands on them.

Oh and I just realized.... someone might want to swap two items on a list.... if there are just an end and a begin node....  I should add a swap for that..... But that seems like it could lead to REALLY big gremlins.... Troll sized, fire breathing, puppy eating gremlins.....


######### swap nodes left ###############
    def swap_left(self, node1, node2):
# or NONE               left                   right             or NONE
#spam-[NONE-ARC--n1-->][<-abc-node1--n2--->][<--n1---node2---lvx->][<--n2---RUM or NONE]
#eggs-[NONE ARC--n2-->][<-abc-node2--n1--->][<--n2---node1---lvx->][<--n1--RUM or NONE]
    

     

        if node1.prev != None and node1.next != None and node2.prev != None and node2.next != None:
            print(" swap 1 ")
            #### get addresses#####
            prevnode1 = node1.prev
            prevnode2 = node2.prev
       
         
            if prevnode1 == node2: ###  eggs -
                #node1.next = node2
                #node2.prev = node1
                print(" eggs ")
                oldARC = node2.prev
                node2.prev.next = node1
                oldRUM = node1.next
                node1.next.prev = node2
                node1.prev = oldARC
                node2.next = oldRUM
                node1.next = node2
                node2.prev = node1
                #oldARC.next = node2
                #oldRUM.prev = node1
                print(node1)
                print(node2)

            elif prevnode2 == node1:
                print("spam") ###  spam-   
                #node1.prev = node2
                #node2.next = node1
                oldARC = node1.prev
                node1.prev.next = node2
                node2.prev = oldARC
                oldRUM = node2.next
                node2.next.prev = node1
                node1.next = oldRUM
                node2.next = node1
                node1.prev = node2
                print(f"oldArc = {oldARC}")
                print(f"oldRUM = {oldRUM}")
                print(node1)
                print(node2)
            else:
                print(" THESE nodes can not be swapped! ")
             

       
        elif node1.prev == None and node2.next != None:
            print("swap 2 (begin node ")
            ### this one works!!!  WOOT! ###
# or NONE               left                   right             or NONE
#[NONE----node1--n2--->][<--n1---node2---nlink--->][<--n2---lvx or NONE]
#[NONE----node2--n1--->][<--n2---node1---nlink--->][<--n1---lvx or NONE]
            # if node1 prev is none... node1 is begin.
            self.begin = node2
            nlink = node2.next
            node2.prev = None
            node2.next = node1
            node1.prev = node2
            node1.next = nlink
            nlink.prev = node1

        elif node2.next== None and node1.next != None:
            print(" swap 3 (end node)")
            ### node2 is the end of the list:
##[<--plink---- node1 --- n2 ---->][ <---n1-- node2-- NONE]
##[<--plink---- node2 --- n1 ---->][ <---n2-- node1-- NONE]
            self.end = node1
            plink = node1.prev
            node1.prev.next = node2
            node1.next = None
            node1.prev = node2
            node2.next = node1
            node2.prev = plink
         
         

        elif node2.prev == None and node1.next != None:
            print("swap (begin node) 2 - B")
           #node2.prev = None, node2 is self.begin of list
# or NONE               left                   right             or NONE
#[NONE----node2--n1--->][<--n2---node1---nlink->][<--n1---lvx or NONE]
#[NONE----node1--n2--->][<--n1---node2---nlink->][<--n2---lvx or NONE]
            # if node1 prev is none... node1 is begin.
            self.begin = node1
            nlink = node1.next
            node1.prev = None
            node1.next = node2
            node2.prev = node1
            node2.next = nlink
            nlink.prev = node2

        elif node1.next== None and node2.next != None:
            print("swap 3 - B (end node) ")
            ### node1 is the end of the list:
##[<--plink---- node2 --- n1 ---->][ <---n2-- node1-- NONE]
##[<--plink---- node1 --- n2 ---->][ <---n1-- node2-- NONE]
            self.end = node2
            plink = node2.prev
            node2.prev.next = node1
            node2.next = None
            node2.prev = node1
            node1.next = node2
            node1.prev = plink
         
     
         
        else:
            print("swap 4")
            print(" THIS should not take place.... ")
            print(" Are you sure the nodes are connected next to each other?")
            print(" They may not be in this list.....")
         


########## END  swap nodes left ##########