NLP Decision Tree

1. make sure main.py, attributes.py, decision_tree.py, and the test and training .txt files are all in the same folder
2. in main.py under the driver code section, you can change the max_depth and num_trials vars to produce different results
3. run the program:
   1. run in command line by navigating to directory of main.py and typing python main.py
   2. or run in IDE
4. the program will run the evaluation routine (as specified in the project specs) and then show the results:
   1. a table with pairing between number of training examples & accuracy will be printed out
   2. a window will appear to show the graphed relationship between the number of training examples & accuracy