Remove groups that contain certain strings

Question

I have an issue about removing the groups that contain certain strings in its rows for example if includes .. I would like to achive this without breaking the p

Answer 1

Here is one option in base R with subset and table

subset(df, gr %in% names(which(!table(gr, grepl("\\.", vals))[,2])))
#  vals gr
#1 good  1
#2  bad  1
#3 ugly  1