recursion-visualiser 1.0.1

A small python package to visualise recursive function on Python. It draws recursion tree

Recursion Visualiser

Recursion visualiser is a python tool that visualizes recursion tree with animation and draws recursion tree for recursive function. It works with almost any type of recursive function. Just add the recursion-visualiser decorator to your function and let it do the rest of the work.

Installation

The only dependency for recursion visualiser is Graphviz which you can download from here

• Download graphviz binary
• Add graphviz bin to path manually or by adding the following line on your script. Change the installation directory according to your installation path

# Set it to bin folder of graphviz  
os.environ["PATH"] += os.pathsep +  'C:/Program Files (x86)/Graphviz2.38/bin/'  

The easiest way to install recursion-visualiser package is from pypi

pip install recursion-visualiser

The preferred way to import the class from the package is as:

from visualiser.visualiser import Visualiser as vs

Example

1. Fibonacci

Let's draw the recursion tree for fibonacci number.
Here is how the simple code looks like

def fib(n):  
    if n <= 1: 
        return n 
    return fib(n - 1) + fib(n - 2)  

print(fib(6))  

Now we want to draw the recursion tree for this function. It is as simple as adding a decorator

# Author: Bishal Sarang

# Import Visualiser class from module visualiser
from visualiser.visualiser import Visualiser as vs

# Add decorator
# Decorator accepts arguments: ignore_args and show_argument_name
@vs()
def fib(n):
    if n <= 1:
        return n
    return fib(n=n - 1) + fib(n=n - 2)


def main():
    # Call function
    print(fib(n=6))
    # Save recursion tree to a file
    vs.make_animation("fibonacci.gif", delay=2)


if __name__ == "__main__":
    main()

Here are the changes required:

• Add decorator Visualiser which accepts optional arguments ignore_args, show_argument_name and 'show_return_value'
• Change every function calls to pass as keyword arguments.
• Make_animation

The output image are saved as "fibonacci.gif" and "fibonacci.png"

Here is how the recursion tree looks like:
Animation:

Find other examples : here and read more about recursion-visualiser here

TODO:

• Minimal working version
• Upload package to pypi
• Support animation
• Support aliasing for function name
• Show repeated states
• Support node_color, backgroundcolor etc
• Refactor
• Handle base cases
• Make more beautiful trees