Source code for evalml.pipelines.utils

import json

from .binary_classification_pipeline import BinaryClassificationPipeline
from .generated_pipelines import (
    GeneratedPipelineBinary,
    GeneratedPipelineMulticlass,
    GeneratedPipelineRegression,
    GeneratedPipelineTimeSeriesBinary,
    GeneratedPipelineTimeSeriesMulticlass,
    GeneratedPipelineTimeSeriesRegression
)
from .multiclass_classification_pipeline import (
    MulticlassClassificationPipeline
)
from .regression_pipeline import RegressionPipeline
from .time_series_classification_pipelines import (
    TimeSeriesBinaryClassificationPipeline,
    TimeSeriesMulticlassClassificationPipeline
)
from .time_series_regression_pipeline import TimeSeriesRegressionPipeline

from evalml.model_family import ModelFamily
from evalml.pipelines import PipelineBase
from evalml.pipelines.components import (  # noqa: F401
    CatBoostClassifier,
    CatBoostRegressor,
    ComponentBase,
    DateTimeFeaturizer,
    DelayedFeatureTransformer,
    DropNullColumns,
    Estimator,
    Imputer,
    OneHotEncoder,
    RandomForestClassifier,
    StackedEnsembleClassifier,
    StackedEnsembleRegressor,
    StandardScaler,
    TextFeaturizer
)
from evalml.pipelines.components.utils import all_components, get_estimators
from evalml.problem_types import (
    ProblemTypes,
    handle_problem_types,
    is_time_series
)
from evalml.utils import get_logger
from evalml.utils.gen_utils import _convert_to_woodwork_structure

logger = get_logger(__file__)


def _get_preprocessing_components(X, y, problem_type, text_columns, estimator_class):
    """Given input data, target data and an estimator class, construct a recommended preprocessing chain to be combined with the estimator and trained on the provided data.

    Arguments:
        X (ww.DataTable): The input data of shape [n_samples, n_features]
        y (ww.DataColumn): The target data of length [n_samples]
        problem_type (ProblemTypes or str): Problem type
        text_columns (list): feature names which should be treated as text features
        estimator_class (class): A class which subclasses Estimator estimator for pipeline

    Returns:
        list[Transformer]: A list of applicable preprocessing components to use with the estimator
    """

    X_pd = X.to_dataframe()
    pp_components = []
    all_null_cols = X_pd.columns[X_pd.isnull().all()]
    if len(all_null_cols) > 0:
        pp_components.append(DropNullColumns)

    pp_components.append(Imputer)

    if text_columns:
        pp_components.append(TextFeaturizer)

    datetime_cols = X.select(["Datetime"])
    add_datetime_featurizer = len(datetime_cols.columns) > 0
    if add_datetime_featurizer:
        pp_components.append(DateTimeFeaturizer)

    if is_time_series(problem_type):
        pp_components.append(DelayedFeatureTransformer)

    categorical_cols = X.select('category')
    if len(categorical_cols.columns) > 0 and estimator_class not in {CatBoostClassifier, CatBoostRegressor}:
        pp_components.append(OneHotEncoder)

    if estimator_class.model_family == ModelFamily.LINEAR_MODEL:
        pp_components.append(StandardScaler)
    return pp_components


def _get_pipeline_base_class(problem_type):
    """Returns pipeline base class for problem_type"""
    if problem_type == ProblemTypes.BINARY:
        return BinaryClassificationPipeline
    elif problem_type == ProblemTypes.MULTICLASS:
        return MulticlassClassificationPipeline
    elif problem_type == ProblemTypes.REGRESSION:
        return RegressionPipeline
    elif problem_type == ProblemTypes.TIME_SERIES_REGRESSION:
        return TimeSeriesRegressionPipeline
    elif problem_type == ProblemTypes.TIME_SERIES_BINARY:
        return TimeSeriesBinaryClassificationPipeline
    else:
        return TimeSeriesMulticlassClassificationPipeline


[docs]def make_pipeline(X, y, estimator, problem_type, custom_hyperparameters=None, text_columns=None): """Given input data, target data, an estimator class and the problem type, generates a pipeline class with a preprocessing chain which was recommended based on the inputs. The pipeline will be a subclass of the appropriate pipeline base class for the specified problem_type. Arguments: X (pd.DataFrame, ww.DataTable): The input data of shape [n_samples, n_features] y (pd.Series, ww.DataColumn): The target data of length [n_samples] estimator (Estimator): Estimator for pipeline problem_type (ProblemTypes or str): Problem type for pipeline to generate custom_hyperparameters (dictionary): Dictionary of custom hyperparameters, with component name as key and dictionary of parameters as the value text_columns (list): feature names which should be treated as text features. Defaults to None. Returns: class: PipelineBase subclass with dynamically generated preprocessing components and specified estimator """ X = _convert_to_woodwork_structure(X) y = _convert_to_woodwork_structure(y) problem_type = handle_problem_types(problem_type) if estimator not in get_estimators(problem_type): raise ValueError(f"{estimator.name} is not a valid estimator for problem type") preprocessing_components = _get_preprocessing_components(X, y, problem_type, text_columns, estimator) complete_component_graph = preprocessing_components + [estimator] if custom_hyperparameters and not isinstance(custom_hyperparameters, dict): raise ValueError(f"if custom_hyperparameters provided, must be dictionary. Received {type(custom_hyperparameters)}") hyperparameters = custom_hyperparameters base_class = _get_pipeline_base_class(problem_type) class GeneratedPipeline(base_class): custom_name = f"{estimator.name} w/ {' + '.join([component.name for component in preprocessing_components])}" component_graph = complete_component_graph custom_hyperparameters = hyperparameters return GeneratedPipeline
def get_generated_pipeline_class(problem_type): """Returns the class for the generated pipeline based on the problem type Arguments: problem_type (ProblemTypes): The problem_type that the pipeline is for Returns: GeneratedPipelineClass (GeneratedPipelineClass): The generated pipeline class for the problem type """ try: return {ProblemTypes.BINARY: GeneratedPipelineBinary, ProblemTypes.MULTICLASS: GeneratedPipelineMulticlass, ProblemTypes.REGRESSION: GeneratedPipelineRegression, ProblemTypes.TIME_SERIES_REGRESSION: GeneratedPipelineTimeSeriesRegression, ProblemTypes.TIME_SERIES_BINARY: GeneratedPipelineTimeSeriesBinary, ProblemTypes.TIME_SERIES_MULTICLASS: GeneratedPipelineTimeSeriesMulticlass}[problem_type] except KeyError: raise ValueError("ProblemType {} not recognized".format(problem_type))
[docs]def make_pipeline_from_components(component_instances, problem_type, custom_name=None, random_state=0): """Given a list of component instances and the problem type, an pipeline instance is generated with the component instances. The pipeline will be a subclass of the appropriate pipeline base class for the specified problem_type. The pipeline will be untrained, even if the input components are already trained. A custom name for the pipeline can optionally be specified; otherwise the default pipeline name will be 'Templated Pipeline'. Arguments: component_instances (list): a list of all of the components to include in the pipeline problem_type (str or ProblemTypes): problem type for the pipeline to generate custom_name (string): a name for the new pipeline random_state (int): Random seed used to intialize the pipeline. Returns: Pipeline instance with component instances and specified estimator created from given random state. Example: >>> components = [Imputer(), StandardScaler(), RandomForestClassifier()] >>> pipeline = make_pipeline_from_components(components, problem_type="binary") >>> pipeline.describe() """ for i, component in enumerate(component_instances): if not isinstance(component, ComponentBase): raise TypeError("Every element of `component_instances` must be an instance of ComponentBase") if i == len(component_instances) - 1 and not isinstance(component, Estimator): raise ValueError("Pipeline needs to have an estimator at the last position of the component list") if custom_name and not isinstance(custom_name, str): raise TypeError("Custom pipeline name must be a string") pipeline_name = custom_name problem_type = handle_problem_types(problem_type) class TemplatedPipeline(_get_pipeline_base_class(problem_type)): custom_name = pipeline_name component_graph = [c.__class__ for c in component_instances] return TemplatedPipeline({c.name: c.parameters for c in component_instances}, random_state=random_state)
[docs]def generate_pipeline_code(element): """Creates and returns a string that contains the Python imports and code required for running the EvalML pipeline. Arguments: element (pipeline instance): The instance of the pipeline to generate string Python code Returns: String representation of Python code that can be run separately in order to recreate the pipeline instance. Does not include code for custom component implementation. """ # hold the imports needed and add code to end code_strings = ['import json'] if not isinstance(element, PipelineBase): raise ValueError("Element must be a pipeline instance, received {}".format(type(element))) if isinstance(element.component_graph, dict): raise ValueError("Code generation for nonlinear pipelines is not supported yet") component_graph_string = ',\n\t\t'.join([com.__class__.__name__ if com.__class__ not in all_components() else "'{}'".format(com.name) for com in element]) code_strings.append("from {} import {}".format(element.__class__.__bases__[0].__module__, element.__class__.__bases__[0].__name__)) # check for other attributes associated with pipeline (ie name, custom_hyperparameters) pipeline_list = [] for k, v in sorted(list(filter(lambda item: item[0][0] != '_', element.__class__.__dict__.items())), key=lambda x: x[0]): if k == 'component_graph': continue pipeline_list += ["{} = '{}'".format(k, v)] if isinstance(v, str) else ["{} = {}".format(k, v)] pipeline_string = "\t" + "\n\t".join(pipeline_list) + "\n" if len(pipeline_list) else "" try: ret = json.dumps(element.parameters, indent='\t') except TypeError: raise TypeError(f"Value {element.parameters} cannot be JSON-serialized") # create the base string for the pipeline base_string = "\nclass {0}({1}):\n" \ "\tcomponent_graph = [\n\t\t{2}\n\t]\n" \ "{3}" \ "\nparameters = json.loads(\"\"\"{4}\"\"\")\n" \ "pipeline = {0}(parameters)" \ .format(element.__class__.__name__, element.__class__.__bases__[0].__name__, component_graph_string, pipeline_string, ret) code_strings.append(base_string) return "\n".join(code_strings)
def _make_stacked_ensemble_pipeline(input_pipelines, problem_type, n_jobs=-1, random_state=0): """ Creates a pipeline with a stacked ensemble estimator. Arguments: input_pipelines (list(PipelineBase or subclass obj)): List of pipeline instances to use as the base estimators for the stacked ensemble. This must not be None or an empty list or else EnsembleMissingPipelinesError will be raised. problem_type (ProblemType): problem type of pipeline n_jobs (int or None): Integer describing level of parallelism used for pipelines. None and 1 are equivalent. If set to -1, all CPUs are used. For n_jobs below -1, (n_cpus + 1 + n_jobs) are used. Defaults to -1. Returns: Pipeline with appropriate stacked ensemble estimator. """ if problem_type in [ProblemTypes.BINARY, ProblemTypes.MULTICLASS]: return make_pipeline_from_components([StackedEnsembleClassifier(input_pipelines, n_jobs=n_jobs)], problem_type, custom_name="Stacked Ensemble Classification Pipeline", random_state=random_state) else: return make_pipeline_from_components([StackedEnsembleRegressor(input_pipelines, n_jobs=n_jobs)], problem_type, custom_name="Stacked Ensemble Regression Pipeline", random_state=random_state)