pythonvalidationdatabricksmlflowautoml

How to validate automl result on the Databricks with a separate dataset


I was performing AutoML feature on the Databricks. But I want to validate the model on the separate dataset.

Since I'm not super aware of the MLFlow, I tried to insert new dataset inside split_test_df with reading it first. But it didn't worked out.

The code inside notebook looks the following:

import mlflow
import databricks.automl_runtime

target_col = "my_target_column"

from mlflow.tracking import MlflowClient
import os
import uuid
import shutil
import pandas as pd

# Create temp directory to download input data from MLflow
input_temp_dir = os.path.join(os.environ["SPARK_LOCAL_DIRS"], "tmp", str(uuid.uuid4())[:8])
os.makedirs(input_temp_dir)


# Download the artifact and read it into a pandas DataFrame
input_client = MlflowClient()
input_data_path = input_client.download_artifacts("some_numbers_and_letters", "data", input_temp_dir)

df_loaded = pd.read_parquet(os.path.join(input_data_path, "training_data"))
# Delete the temp data
shutil.rmtree(input_temp_dir)

# Preview data
df_loaded.head(5)

df = spark.read.format('delta').load(
  'dbfs:/user/hive/warehouse/test_df/',
  header=True,
  inferSchema=True
)

from databricks.automl_runtime.sklearn.column_selector import ColumnSelector
supported_cols = ["there_are_my_columns"]
col_selector = ColumnSelector(supported_cols)


from sklearn.compose import ColumnTransformer
from sklearn.impute import SimpleImputer
from sklearn.pipeline import Pipeline
from sklearn.preprocessing import FunctionTransformer, StandardScaler

num_imputers = []
num_imputers.append(("impute_mean", SimpleImputer(), ["there_are_my_columns"]))

numerical_pipeline = Pipeline(steps=[
    ("converter", FunctionTransformer(lambda df: df.apply(pd.to_numeric, errors="coerce"))),
    ("imputers", ColumnTransformer(num_imputers)),
    ("standardizer", StandardScaler()),
])

numerical_transformers = [("there_are_my_columns"])]

from sklearn.compose import ColumnTransformer

transformers = numerical_transformers

preprocessor = ColumnTransformer(transformers, remainder="passthrough", sparse_threshold=0)

# AutoML completed train - validation - test split internally and used _automl_split_col_3da1 to specify the set
split_train_df = df_loaded.loc[df_loaded._automl_split_col_3da1 == "train"]
split_val_df = df_loaded.loc[df_loaded._automl_split_col_3da1 == "val"]
split_test_df = df.loc[df._automl_split_col_3da1 == 'test']  # here it throws an error that ttributeError: 'DataFrame' object has no attribute 'loc'

# Separate target column from features and drop _automl_split_col_3da1
X_train = split_train_df.drop([target_col, "_automl_split_col_3da1"], axis=1)
y_train = split_train_df[target_col]

X_val = split_val_df.drop([target_col, "_automl_split_col_3da1"], axis=1)
y_val = split_val_df[target_col]

X_test = split_test_df.drop(target_col)
y_test = split_test_df[target_col]

And even if it was read and processed to the model in MLFlow context I still don't see any changes in the confusion matrix since I'm also not sure if it based on the test data and how accurate the result was.


Solution

  • It is possible to do that via the notebook and re-assigning of the validation dataset to the dataset on which you want to perform validation.