def create_X_y(train, val, test, target):
    """creates X_ and y_ dataframes from train, val, test for model building"""
    X_train = train.drop(target, axis=1)
    y_train = train[target]
    X_val = val.drop(target, axis=1)
    y_val = val[target]
    X_test = test.drop(target, axis=1)
    y_test = test[target]
    return X_train, y_train, X_val, y_val, X_test, y_test