How can I implement a tree in Python?

Question

I am trying to construct a General tree.

Are there any built-in data structures in Python to implement it?

Answer 1

anytree

I recommend https://pypi.python.org/pypi/anytree (I am the author)

Example

from anytree import Node, RenderTree

udo = Node("Udo")
marc = Node("Marc", parent=udo)
lian = Node("Lian", parent=marc)
dan = Node("Dan", parent=udo)
jet = Node("Jet", parent=dan)
jan = Node("Jan", parent=dan)
joe = Node("Joe", parent=dan)

print(udo)
Node('/Udo')
print(joe)
Node('/Udo/Dan/Joe')

for pre, fill, node in RenderTree(udo):
    print("%s%s" % (pre, node.name))
Udo
├── Marc
│   └── Lian
└── Dan
    ├── Jet
    ├── Jan
    └── Joe

print(dan.children)
(Node('/Udo/Dan/Jet'), Node('/Udo/Dan/Jan'), Node('/Udo/Dan/Joe'))

Features

anytree has also a powerful API with:

• simple tree creation
• simple tree modification
• pre-order tree iteration
• post-order tree iteration
• resolve relative and absolute node paths
• walking from one node to an other.
• tree rendering (see example above)
• node attach/detach hookups