alpha beta

 tree = [[[5, 1, 2], [8, -8, -9]], [[9, 4, 5], [-3, 4, 3]]]

root = 0

pruned = 0

def children(branch, depth, alpha, beta):

 global tree

 global root

 global pruned

 i = 0

 for child in branch:

 if type(child) is list:

 (nalpha, nbeta) = children(child, depth + 1, alpha, beta)

 if depth % 2 == 1:

 beta = nalpha if nalpha < beta else beta

 else:

 alpha = nbeta if nbeta > alpha else alpha

 branch[i] = alpha if depth % 2 == 0 else beta

 i += 1

 else:

 if depth % 2 == 0 and alpha < child:

 alpha = child

 if depth % 2 == 1 and beta > child:

 beta = child

 if alpha >= beta:

 pruned += 1

 break

 if depth == root:

 tree = alpha if root == 0 else beta

 return (alpha, beta)

def alphabeta(in_tree=tree, start=root, upper=-15, lower=15):

 global tree

global pruned

 global root

 (alpha, beta) = children(tree, start, upper, lower)

 if __name__ == "__main__":

 print ("(alpha, beta): ", alpha, beta)

 print ("Result: ", tree)

 print ("Times pruned: ", pruned)

 return (alpha, beta, tree, pruned)

if __name__ == "__main__":

 alphabeta(None)