node = TreeNode('menubar')

# --- A node can be used like a dictionary
#     It will, by default, have a key 'label' set
#        to the string provided

print(node['label'])

# menubar

node['mykey'] = 'myvalue'
print(f"node has {len(node)} keys")

# node has 2 keys

firstChild = TreeNode('firstchild')
node.appendChildNode(firstChild)

secondChild = TreeNode('secondchild')
node.appendChildNode(secondChild)

thirdChild = TreeNode('thirdchild')
node.appendChildNode(secondChild)

print(f"node has {node.numChildren()} children")

# node has 3 children

print(f"node has {node.numSiblings()} siblings")
print(f"firstChild has {firstChild.numSiblings()} siblings")

# node has 0 siblings
# firstChild has 2 siblings

tokzr = RETokenizer()
tokzr.add('INTEGER', r'\d+')
tokzr.add('STRING',  r'"([^"]*)"', 1)
tokzr.add('STRING',  r"'([^']*)'", 1)

lTokens = list(tokzr.tokens('"mystring"'
                           ' + '
                           "'other'"))
assert lTokens == [
	('STRING', 'mystring'),
	('OTHER',  '+'),
	('STRING', 'other'),
	]

s = '''
	* menubar
		file
			new
			open
		edit
			undo
	* layout
		row
			EditField
			SelectField
'''
(tree, hSubTrees) = parsePLL(s)

assert len(hSubTrees) == 2

See the file

All unit tests appear at the end of the source file itself
They can be run using pytest