Getting 'ValueError: shapes not aligned' on SciKit Linear Regression

Question

Quite new to SciKit and linear algebra/machine learning with Python in general, so I can\'t seem to solve the following:

I have a training set and a test set of data, co

Answer 1

For anyone interested: I ended up merging the train and test set, then generating the dummies, and then splitting the data again at exactly the same fraction. That way there wasn't any issue with different shapes anymore, as it generated exactly the same dummy data.