I found Scala for Data Science by Pascal Bugnion to be great when I was learning Scala. Granted, this was for a Big Data class at the university level that was

I found Scala for Data Science by Pascal Bugnion to be great when I was learning Scala. Granted, this was for a Big Data class at the university level that was covering Spark and Scala mostly. However, I remember the book to be very clear and digestible.