Set the types associated with the dotpath in the frame. If the frame “f1” has the following dotpaths - .title, .authors, and .year then set the types as string, string and year. Not the order the dotpaths are defined is the order you’re apply the types.
dataset pubs.ds frame-types f1 string string year
In python
err = dataset.frame_types('pubs.ds', 'f1', ['string', 'string', 'year'])