Closed
Description
Describe the bug
A common use case is to use Pipeline to transform the feature set and to wrap it with TransformedTargetRegressor to transform the response variable. But when used in combination and calling fit on the TransformedTargetRegressor object, the model internal to the Pipeline is not actually fit.
Steps/Code to Reproduce
from sklearn.preprocessing import StandardScaler
from sklearn_pandas import DataFrameMapper
from xgboost import XGBRegressor
from sklearn.compose import TransformedTargetRegressor
from sklearn import datasets
from sklearn.pipeline import Pipeline
import pandas as pd
import numpy as np
iris = datasets.load_iris()
df = pd.DataFrame(iris.data, columns=iris.feature_names)
y_col = "sepal length (cm)"
x_cols = [x for x in iris.feature_names if x != y_col]
model = XGBRegressor()
mod_pipeline = Pipeline([("scaler", StandardScaler()), ("model", model)])
mod_pipeline = TransformedTargetRegressor(regressor=mod_pipeline, func=np.log1p, inverse_func=np.expm1)
mod_pipeline.fit(df[x_cols], df[y_col])
mod_pipeline.regressor['model'].__sklearn_is_fitted__()Expected Results
True
Actual Results
False
Versions
System:
python: 3.11.9 (main, May 17 2024, 12:31:23) [Clang 14.0.3 (clang-1403.0.22.14.1)]
executable: /Users/jmaddalena/projects/vesta/.venv/bin/python
machine: macOS-14.5-x86_64-i386-64bit
Python dependencies:
sklearn: 1.4.1.post1
pip: 24.0
setuptools: 66.1.1
numpy: 1.26.4
scipy: 1.12.0
Cython: 3.0.9
pandas: 2.2.2
matplotlib: 3.8.3
joblib: 1.3.2
threadpoolctl: 3.3.0
Built with OpenMP: True
threadpoolctl info:
user_api: openmp
internal_api: openmp
num_threads: 11
prefix: libomp
filepath: /Users/jmaddalena/projects/vesta/.venv/lib/python3.11/site-packages/sklearn/.dylibs/libomp.dylib
version: None
user_api: blas
internal_api: openblas
num_threads: 11
prefix: libopenblas
filepath: /Users/jmaddalena/projects/vesta/.venv/lib/python3.11/site-packages/numpy/.dylibs/libopenblas64_.0.dylib
version: 0.3.23.dev
threading_layer: pthreads
architecture: Nehalem
user_api: blas
internal_api: openblas
num_threads: 11
prefix: libopenblas
filepath: /Users/jmaddalena/projects/vesta/.venv/lib/python3.11/site-packages/scipy/.dylibs/libopenblas.0.dylib
version: 0.3.21.dev
threading_layer: pthreads
architecture: Nehalem