How to fix: ValueError: too many values to unpack (expected 2) PCA

Question

I have two variables:

numeric_cols = ['FamilyMembers', 'ChronicDiseases']

and I have this pipeline:

numeric_transformer = Pipeline(
                        steps=[('scaler', StandardScaler(),
                                'red_dim', PCA())
])

and I get the error:

ValueError: too many values to unpack (expected 2)

I get the same error with 4 variables.

How can I fix this error?

Answer 1

Pipeline's steps should be a list of (name, transform) tuples as follows:

numeric_transformer = Pipeline(
                        steps=[('scaler', StandardScaler()),
                                ('red_dim', PCA())
                              ]
)