Data Science Algorithms in a Week - Second Edition

Implementation

We implement an ID3 algorithm that constructs a decision tree for the data given in a CSV file. All sources are in the chapter directory. The most important parts of the source code are given here:

# source_code/3/construct_decision_tree.py# Constructs a decision tree from data specified in a CSV file.
# Format of a CSV file:
# Each data item is written on one line, with its variables separated
# by a comma. The last variable is used as a decision variable to
# branch a node and construct the decision tree.

import math
# anytree module is used to visualize the decision tree constructed by# this ID3 algorithm.
from anytree import Node, RenderTree
import sys
sys.path.append('../common')
import common
import decision_tree

# Program ...