recursion-visualiser 1.0.3
A small python package to visualise recursive function on Python. It draws recursion tree
Requires Python: >=3.6

# Recursion Visualiser  

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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  
  ### 1. Installing graphviz
  #### Windows
The only dependency for recursion visualiser is Graphviz
- Download  [graphviz binary](https://www2.graphviz.org/Packages/stable/windows/10/msbuild/Release/Win32/)  
- 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/'  
```  
  
  #### Ubuntu 
  - Install graphviz
  ```
   sudo apt install graphviz
  ```

>  The instructions to install graphviz for other operating system is available  [here](https://www.graphviz.org/download/#linux)

### 2. Installing recursion-visualiser

The easiest way to  install ```recursion-visualiser``` package is from [pypi](https://pypi.org/project/recursion-visualiser/)
```
pip install recursion-visualiser
```


An alternative way is to clone the repository and install all the requirements.
```
pip install -r requirements.txt
```

## Alternative Installation using Docker
If you have `docker` and `docker-compose` installed then you can install `recursion-tree-visualiser`  using `Docker` and `docker-compose.yml` file
1.  Download `Docker` file from repo
```bash
curl https://raw.githubusercontent.com/Bishalsarang/Recursion-Tree-Visualizer/master/Dockerfile --output Dockerfile
```

3. Download `docker-compose.yml`
```bash
curl https://raw.githubusercontent.com/Bishalsarang/Recursion-Tree-Visualizer/master/docker-compose.yml --output docker-compose.yml
```
5. Start docker container
```bash
CURRENT_UID=$(id -u):$(id -g) docker-compose up
```

7. Run any python scripts and run using
```
docker-compose exec vs python fibonacci.py
```
## Usage 
The preferred way to import the decorator class from the package is as:
```python
from visualiser.visualiser import Visualiser as vs
```
### 1.  Fibonacci  
Let's draw the recursion tree for fibonacci number.  
Here is how the simple code looks like  
```python  
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  
```python  
# Author: Bishal Sarang

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

# Add decorator
# Decorator accepts optional arguments: ignore_args , show_argument_name, show_return_value and node_properties_kwargs
@vs(node_properties_kwargs={"shape":"record", "color":"#f57542", "style":"filled", "fillcolor":"grey"})
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:
![enter image description here](https://raw.githubusercontent.com/Bishalsarang/Recursion-Tree-Visualizer/master/examples/fibonacci.gif)  
  
![enter image description here](https://raw.githubusercontent.com/Bishalsarang/Recursion-Tree-Visualizer/master/examples/fibonacci.png)  


# Support:
Find other examples [here](https://github.com/Bishalsarang/Recursion-Tree-Visualizer/tree/master/examples)
and read more about **recursion-visualiser** [here](https://github.com/Bishalsarang/Recursion-Tree-Visualizer/blob/master/Examples.md)


## TODO:  
 - [x] Minimal working version  
 - [x] Upload package to pypi  
 - [x] Support animation
 - [x] Add node styles
 - [ ] Support aliasing for function name
 - [ ] Show repeated states
 - [x] Support node_color, backgroundcolor etc
 - [ ] Refactor  
 - [ ] Handle base cases  
 - [ ] Make more beautiful trees