Added code vor tree validation.

def load_data(filename):

    print (os.getcwd())

    with open(filename, newline='') as csvfile:

        reader = csv.reader(csvfile)

        try:

            data = [];

            data = []

            for row in reader:

                data.append(row)

            print(data)

            return np.array(data)

        except csv.Error as e:

            sys.exit("file {}, line {}: {}".format())

            sys.exit("file {}, line {}".format(filename, row))

def plant_trees(data):

    return tree

def validation():

    pass

def validation(tree, data):

    confusion_matrix = np.zeros((3, 3))

    parameters = np.array(data)

    classes = data[len(data)-1]

    for parameter, pclass in zip(parameters, classes):

        result = tree.predict(parameter)

        confusion_matrix[result, pclass] += 1

    return confusion_matrix

def report(tree, confusion_matrix):

    print(tree)

    print(confusion_matrix)

def store():

def store(tree, confusion_matrix):

    pass

    print("Loading file {}".format(filename))

    data = load_data(filename)

    tree = plant_trees(data)

    validation(tree)

    store(tree)

    confusion_matrix = validation(tree)

    report(tree, confusion_matrix)

    store(tree, confusion_matrix)

if __name__ == '__main__':