class DB(object):
def __init__(self, f):
self.storage = Storage(f)
self.tree = BinaryTree(self.storage)
def assert_not_closed(self):
if self.storage.closed:
print("db closed")
raise ValueError("db closed")
def close(self):
self.storage.close()
def update(self):
self.assert_not_closed()
self.tree.update()
def __getitem__(self, key):
self.assert_not_closed()
return self.tree.get(key)
def __setitem__(self, key, value):
self.assert_not_closed()
return self.tree.set(key, value)
def __delitem__(self, key):
self.assert_not_closed()
return self.tree.delete(key)
def __contains__(self, key):
self.assert_not_closed()
try:
self[key]
except KeyError:
return False
else:
return True
def __len__(self):
return len(self.tree)
def listAll(self):
return self.tree.listAll()
def main():
tree = BinaryTree()
tree.set('c', 'C')
tree.set('h', 'H')
tree.set('a', 'A')
tree.set('e', 'E')
tree.set('f', 'F')
tree.set('d', 'D')
tree.set('b', 'B')
tree.set('k', 'K')
tree.set('j', 'J')
tree.set('i', 'I')
tree.set('g', 'G')
tree.set('l', 'L')
print('Lookups:')
print(tree.get('f'))
print(tree.get('b'))
print(tree.get('i'))
print()
print(tree)
print()
print('DFS preorder:')
for key, value in tree.walk_dfs_preorder():
print(key, value)
print()
print('DFS inorder:')
for key, value in tree.walk_dfs_inorder():
print(key, value)
print()
print('DFS postorder:')
for key, value in tree.walk_dfs_postorder():
print(key, value)
print()
print('BFS:')
for key, value in tree.walk_bfs():
print(key, value)
print()
print('Initial tree:')
print(tree)
print()
print('Remove b:')
tree.remove('b')
print(tree)
print()
print('Remove f:')
tree.remove('f')
print(tree)
print()
print('Remove h:')
tree.remove('h')
print(tree)
print()
