PHART: The Python Hierarchical ASCII Representation Tool - A Pure Python graph visualization in ASCII, no external dependencies*
(* except NetworkX, which we should probably mention prominently. We just mean no dependencies of the Perl or PHP/webserver types.)
Because it is necessary? OK, sorry… Actually it had a few other names early on, but when it came time to upload to PyPi, we discovered the early names we chose were already taken so we had to choose a new name. We wanted to mash up the relevant terms (“graph”, “ascii”, “art”, “chart”, and such) and bonus if the new name is a fitting acronym.
In the case of PHART, the acronym made from the first letters of the obvious first words to come to mind was discovered to spell PHART after the non abbreviated words were suggested. Fortuitous; so it had to be.
You may pronounce it the obvious monosyllabic way, or as “eff art”, or perhaps “pee heart”, or any way that you like, so long as the audience you are speaking it to knows it is PHART you are referring to.
The mention of not being Perl or a PHP webapp may appear to be throwing shade at the existing solutions, but it is meant in a good-hearted way. Wrapping the OG Graph::Easy is a straightforeard way to go about it, and a web interface to the same is a project I might create as well, but Perl being installed is not the sure ubiquitous thing it omce was, and spinning up a Docker container in order to add ascii art graph output to a python tool seemed a bit excessive.
Additionally, I’m not sure how I didn’t find pydot2ascii - which is native python - when I first looked for a solution, but even if I had seen it I may not have realized that I could have exported my NX DAG to DOT, and then used pydot2ascii to go from DOT to ascii art.
So now we have PHART, and the ability to render a NX digraph in ASCII/Unicode, read a DOT file, read GraphML, and a few other things in a well-tested Python module published to PyPi. I hope you find it useful.
requires Python >= 3.10 and NetworkX >= 3.3
pip install phart
import networkx as nx
from phart import ASCIIRenderer
# Create a simple graph
G = nx.DiGraph()
G.add_edges_from([("A", "B"), ("A", "C"), ("B", "D")])
# Render it in ASCII
renderer = ASCIIRenderer(G)
print(renderer.render())
[A]
│
v │ v
[B]────[C]
│
│ v
──[D]
The renderer shows edge direction using arrows:
These directional indicators are particularly useful for:
PHART supports multiple character sets for rendering:
--charset unicode (default): Uses Unicode box drawing characters and arrows for
cleaner visualization--charset ascii: Uses only 7-bit ASCII characters, ensuring maximum compatibility
with all terminalsExample:
# Using Unicode (default)
phart graph.dot
# ┌─A─┐
# │ │
# └─B─┘
# Using ASCII only
phart --charset ascii graph.dot
# +-A-+
# | |
# +-B-+
pip install phart[extras]
or using requirements file
pip install -r requirements\extra.txt
>>> dot = '''
... digraph {
... A -> B
... B -> C
... }
... '''
>>> renderer = ASCIIRenderer.from_dot(dot)
>>> print(renderer.render())
A
|
B
|
C
>>>
PHART uses pydot for DOT format support. When processing DOT strings containing multiple graph definitions, only the first graph will be rendered. For more complex DOT processing needs, you can convert your graphs using NetworkX’s various graph reading utilities before passing them to PHART.
PHART supports reading GraphML files:
renderer = ASCIIRenderer.from_graphml("graph.graphml")
print(renderer.render())
PHART can be used from the command line to render graph files:
# Basic usage
phart input.dot
# Save to file instead of stdout
phart input.dot -o output.txt
# GraphML input
phart input.graphml --output viz.txt
# Change node style
phart --style round input.dot
# Force ASCII output (no Unicode)
phart --ascii input.dot
# Adjust spacing
phart --node-spacing 6 --layer-spacing 3 input.dot
MIT License