Issue 1:
Description

Type error thrown when handing over an options dictionary to gridsearchs fit method like so:

grid_search.fit(train[["A", "B"]], train["C"], **fit_options)

This worked for 0.21.3, but doesn't for 0.22.0, so this might be a regression. Behavior change was introduced here: https://github.com/scikit-learn/scikit-learn/blame/master/sklearn/model_selection/_search.py#L651

Steps/Code to Reproduce

from sklearn.linear_model import HuberRegressor
from sklearn.model_selection import GridSearchCV
import pandas as pd

train = pd.DataFrame({"A": [1, 2, 3, 5, 2], "B": [4, 5, 6, 4, 1], "C": [5, 7, 9, 9, 3]})

hyper_parameter_tune = {
"epsilon": [1, 1.5]
}

fit_options = {
"sample_weight": 1
}

gridsearch_params = {
"cv": 2
}

gsearch = GridSearchCV(param_grid=hyper_parameter_tune,
estimator=HuberRegressor(),
**gridsearch_params
)

gsearch.fit(train[["A", "B"]], train["C"], **fit_options)

observation = pd.DataFrame({"A": [5], "B": [2]})

print(gsearch.predict(observation))

Expected Results

No Error thrown: TypeError: Singleton array array(1) cannot be considered a valid collection

Actual Results

Traceback (most recent call last):

File "/home/stepo/PycharmProjects/untitled/test.py", line 24, in

gsearch.fit(train[["A", "B"]], train["C"], groups=None, **fit_options)

File "/home/stepo/PycharmProjects/untitled/venv/lib/python3.7/site-packages/sklearn/model_selection/_search.py", line 652, in fit

fit_params_values = indexable(*fit_params.values())

File "/home/stepo/PycharmProjects/untitled/venv/lib/python3.7/site-packages/sklearn/utils/validation.py", line 237, in indexable

check_consistent_length(*result)

File "/home/stepo/PycharmProjects/untitled/venv/lib/python3.7/site-packages/sklearn/utils/validation.py", line 208, in check_consistent_length

lengths = [_num_samples(X) for X in arrays if X is not None]

File "/home/stepo/PycharmProjects/untitled/venv/lib/python3.7/site-packages/sklearn/utils/validation.py", line 208, in

lengths = [_num_samples(X) for X in arrays if X is not None]

File "/home/stepo/PycharmProjects/untitled/venv/lib/python3.7/site-packages/sklearn/utils/validation.py", line 152, in _num_samples

" a valid collection." % x)

TypeError: Singleton array array(1) cannot be considered a valid collection.

Versions

System:

python: 3.7.5 (default, Nov 20 2019, 09:21:52) [GCC 9.2.1 20191008]

executable: /home/stepo/PycharmProjects/untitled/venv/bin/python

machine: Linux-5.3.0-24-generic-x86_64-with-Ubuntu-19.10-eoan

Python dependencies:

pip: 19.0.3

setuptools: 40.8.0

sklearn: 0.22

numpy: 1.17.4

scipy: 1.3.3

Cython: None

pandas: 0.25.3

matplotlib: None

joblib: 0.14.1

Built with OpenMP: True

Issue 2:
UPDATE May 23 202

Here's a list of the remaining classes:

feature_selection.SelectorMixin

calibration.CalibratedClassifierCV (#15134)

decomposition.DictionaryLearning (#16907)

decomposition.MiniBatchDictionaryLearning (#16907)

decomposition.SparseCoder (#15233)

ensemble.GradientBoostingClassifier

gaussian_process.kernels.CompoundKernel

gaussian_process.kernels.Hyperparameter

gaussian_process.kernels.Kernel

gaussian_process.kernels.PairwiseKernel

inspection.PartialDependenceDisplay

linear_model.PoissonRegressor

linear_model.TweedieRegressor

linear_model.GammaRegressor

metrics.ConfusionMatrixDisplay

metrics.PrecisionRecallDisplay

mixture.BayesianGaussianMixture

mixture.GaussianMixture

multioutput.ClassifierChain (#15211)

multioutput.RegressorChain (#15215)

neighbors.BallTree

neighbors.DistanceMetric

neighbors.KDTree

Most of the docs in classes lack examples. It would be great to add one or two examples similar to this, http://scikit-learn.org/stable/modules/generated/sklearn.linear_model.Lasso.html