K-fold Train

Posted 2021-05-19

# config.py
TRAINING_FILE = "../input/mnist_train_folds.csv"
MODEL_OUTPUT = "../models/"

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# train.py
import os
import config
import joblib
import pandas as pd
from sklearn import metrics
from sklearn import tree
def run(fold):
     # read the training data with folds
     df = pd.read_csv(config.TRAINING_FILE)
     # training data is where kfold is not equal to provided fold
     # also, note that we reset the index
     df_train = df[df.kfold != fold].reset_index(drop=True)
     # validation data is where kfold is equal to provided fold
     df_valid = df[df.kfold == fold].reset_index(drop=True)
     # drop the label column from dataframe and convert it to
     # a numpy array by using .values.
     # target is label column in the dataframe
     x_train = df_train.drop("label", axis=1).values
     y_train = df_train.label.values
     # similarly, for validation, we have
     x_valid = df_valid.drop("label", axis=1).values
     y_valid = df_valid.label.values
     # initialize simple decision tree classifier from sklearn
     clf = tree.DecisionTreeClassifier()
     # fir the model on training data
     clf.fit(x_train, y_train)
     # create predictions for validation samples
     preds = clf.predict(x_valid)
     # calculate & print accuracy
     accuracy = metrics.accuracy_score(y_valid, preds)
     print(f"Fold={fold}, Accuracy={accuracy}")
     # save the model
     joblib.dump(
         clf,
         os.path.join(config.MODEL_OUTPUT, f"dt_{fold}.bin")
     )


if __name__ == "__main__":
    run(fold=0)
    run(fold=1)
    run(fold=2)
    run(fold=3)
    run(fold=4)