treedepth.py

import unittest

def has_branches(tree):
	return len(tree) >= 1

def depth(tree):
	if has_branches(tree):
		return 1 + max(map(depth, tree))
	else:
		return 1
	
class DepthTest(unittest.TestCase):
	def testHasBraches(self):
		tree = []
		self.assertFalse(has_branches(tree))
	def testNoChildren(self):
		tree = []
		self.assertEquals(1, depth(tree))
	def testAChild(self):
		tree = [[]]
		self.assertEquals(2, depth(tree))
	def testChildren(self):
		tree = [[],[[]]]
		self.assertEquals(3, depth(tree))

unittest.main()