This activity doesn't feel like it is a cohesive unit(it seems like its a string of disjoint tutorials). Cards should be added in every so often withing the mini tutorials reminding the student of what this activity is really about(sentiment analysis).
2.md
The styling of dataframe code at the start should be fixed.
3.md
_Some visuals describing this concept of dataframe should be added(something like a result of running groupby on a dataframe or something).
19.md & 20.md
Get better picture of the dataframe output(and cut it up for 19.md)
Activity Wide Issue
2.md
3.md
19.md & 20.md