I think it would make sense to make the following attributes private as opposed to public:

• average_coef_
• average_intercept_
• standard_coef_
• standard_intercept_

The reason for making these attributes private is because:

• average_coef_ and standard_coef_ are there to help determine the value of coef_
• average_intercept_ and standard_intercept_ are there to help determine the value of intercept_
• therefore, none of these intermediary attributes should be exposed to users as public attributes