CODEWITHSUNDEEP
pythonmachine-learningscikit-learn
Melanie
Melanie

Reputation: 1987

Why is this parameter invalid in sklearn's Pipeline?

I am getting the following error for the below code, but cannot figure out why my parameter is invalid. SelectFromModel is a valid input in a Pipeline as it has a fit and transform function. 

ValueError: Invalid parameter sfm_threshold for estimator Pipeline.
Check the list of available parameters with
`estimator.get_params().keys()`


from sklearn.preprocessing import PolynomialFeatures, StandardScaler
from sklearn.linear_model import LassoCV, LinearRegression
from sklearn.feature_selection import SelectFromModel
from sklearn.pipeline import Pipeline

poly = PolynomialFeatures()
std = StandardScaler()
ls = LassoCV(cv=10)
sfm = SelectFromModel(estimator=ls)
lr = LinearRegression()

pipe_lr = Pipeline([('poly', poly),
                    ('std', std),
                    ('sfm', sfm),
                    ('lr', lr)])

param_range_degree = [2, 3]
param_range_threshold = [0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5]

param_grid_lr = [{'poly__degree': param_range_degree,
                  'sfm__threshold': param_range_threshold}]

When I run pipe_lr.get_params().keys() I get the following output, which does in fact include sfm__threshold, which I copy and pasted exactly as is.

 ['std__with_mean',
 'sfm__estimator__precompute',
 'lr__n_jobs',
 'sfm__prefit',
 'poly',
 'sfm__threshold',
 'sfm__estimator__cv',
 'sfm__estimator__max_iter',
 'sfm__estimator__positive',
 'sfm__estimator__n_alphas',
 'std__with_std',
 'sfm__estimator__random_state',
 'std__copy',
 'lr__normalize',
 'sfm__estimator__copy_X',
 'lr',
 'sfm__estimator__n_jobs',
 'poly__interaction_only',
 'sfm__estimator__fit_intercept',
 'sfm__estimator__tol',
 'sfm__estimator',
 'sfm__estimator__verbose',
 'sfm',
 'sfm__estimator__normalize',
 'std',
 'sfm__estimator__selection',
 'poly__degree',
 'lr__copy_X',
 'sfm__estimator__alphas',
 'lr__fit_intercept',
 'steps',
 'poly__include_bias',
 'sfm__estimator__eps']

Upvotes: 2

Views: 1613

Answers (1)

lejlot
lejlot

Reputation: 66775

This is simple typographical error, you pass sfm_threshold and you should sfm__threshold (notice double underscore). At least this is what the error at the very beginning shows.

Upvotes: 6

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