Ascii Tree
Generate beautiful ascii trees.
I think that I shall never see
A graph more lovely than a tree.
A tree whose crucial property
Is loop-free connectivity.
A tree that must be sure to span
So packets can reach every LAN.
First, the root must be selected.
By ID, it is elected.
Least-cost paths from root are traced.
In the tree, these paths are placed.
A mesh is made by folks like me,
Then bridges find a spanning tree.
-Radia Perlman
Installation
git clone ...
cd ...
python3 setup.py install
Usage
This library can print arbitrary trees. This requires you to specify how the value of a node, and list of it's children can be extracted from the node object. For example, consider the following n-ary tree node class
>>> class NTreeNode:
... def __init__(self, val):
... self.val = val
... self.children = []
We can extract it's value and children like
>>> def get_value(node):
... return node.value
...
>>> def get_children(node):
... return node.children
...
First, we'll construct a dummy tree.
>>> root = NTreeNode('Lorem ipsum dolor sit amet')
>>> root.children = [NTreeNode('consectetur adipiscing elit.'), NTreeNode('Etiam laoreet congue')]
>>> root.children[0].children = [NTreeNode('Pellentesque finibus metus eget'), NTreeNode('ante aliquet ullamcorper')]
>>> root.children[1].children = [NTreeNode('Morbi porta, diam at imperdiet venenatis'), NTreeNode('neque eros bibendum tortor, quis')]
Now we can print this as an ascii (the library originally only used ascii characters) tree like
>>> from ascii_tree import make_and_print_tree
>>> make_and_print_tree(root, get_value, get_children)
page: 0
┌───────────────────┐
│ │
│ Lorem ipsum dolo │
│ r sit amet ├────────────────────────────────────┐
│ │ │
└┬──────────────────┘ │
│ │
│ │
│ │
│ │
│ │
┌─────────┴─────────┐ ┌─────────┴─────────┐
│ │ │ │
│ consectetur adip │ │ Etiam laoreet co │
│ iscing elit. ├────────────────────┐ │ ngue │
│ │ │ │ │
└──┬────────────────┘ │ └───────────────────┘
│ │
│ │
│ │
│ │
│ │
┌─────────┴─────────┐ ┌─────────┴─────────┐
│ │ │ │
│ Pellentesque fin │ │ ante aliquet ull │
┌─┤ ibus metus eget ├──┐ │ amcorper │
│ │ │ │ │ │
│ └───────────────────┘ │ └───────────────────┘
│ │
│ │
│ │
│ │
│ │
┌─────────┴─────────┐ ┌─────────┴─────────┐
│ │ │ │
│ Sed nec nibh cur │ │ volutpat lacus a │
│ sus │ │ t, euismod mi │
│ │ │ │
└───────────────────┘ └───────────────────┘
We can also print the tree using only ascii characters like:
>>> update_param('charset', 'ascii')
>>> make_and_print_tree(root, lambda n: n.val, lambda n: n.children)
page: 0
---------------------
| |
| Lorem ipsum dolo |
| r sit amet |-------------------------------------
| | |
--------------------- |
| |
| |
| |
| |
| |
--------------------- ---------------------
| | | |
| consectetur adip | | Etiam laoreet co |
| iscing elit. |--------------------- | ngue |
| | | | |
--------------------- | ---------------------
| |
| |
| |
| |
| |
--------------------- ---------------------
| | | |
| Pellentesque fin | | ante aliquet ull |
--| ibus metus eget |--- | amcorper |
| | | | | |
| --------------------- | ---------------------
| |
| |
| |
| |
| |
--------------------- ---------------------
| | | |
| Sed nec nibh cur | | volutpat lacus a |
| sus | | t, euismod mi |
| | | |
--------------------- ---------------------
Currently the screen width (the maximum character width assumed by the tree) is 180.
This can be updated like:
>>> from ascii_tree import update_param
>>> update_param('screen_width', 120)
>>> make_and_print_tree(root, get_value, get_children)
These params can be updated thus: screen_width, margin (distance between nodes),
padding (distance between box contents and border) and box_max_width.
See more examples here.
The call_graph library uses ascii_tree to print call graphs.
Notes
-
Only supports
python3 -
Boxes/nodes can have be upto max width, beyond which their contents are wrapped.
-
If a tree is too wide, then it is split at a node. Practically, this means that some children go one side of the split, and the rest on the other side. When a node is split, an information box is added as a child to the node, which shows the page number where tree is continued.