Python example Tower of Hanoi problem

. 1 COUNT = 0
 2  DEF Hanoi (n-, src, dst, mid): # n-represents the number of disks, src denotes a source column, dst indicates the purpose of the column, mid column represents a transition 
. 3      Global COUNT    # global variable defined, the function internal global reserved word 
. 4      IF n-==. 1 :
 . 5          Print ( " {}: {} -> {} " .format (. 1 , the src, DST))
 . 6          COUNT + =. 1
 . 7      the else :     # the n-1 th disc on the mid, the last disc is placed on dst 
. 8          Hanoi (. 1-n-, the src, mid, dst)   # called twice 
. 9          Print ( " {}: {} -> {} ".format(n,src,dst))
10         count +=1
11         hanoi(n-1,mid,dst,src)
12 hanoi(3,"A","C","B")
13 print(count)

The output is:

1:A->C
2:A->B
1:C->B
3:A->C
1:B->A
2:B->C
1:A->C
7