根据列中的公共值将大型数据aframe分割为一组数据帧

I have a data frame with 10 columns, collecting actions of "users", where one of the columns contains an ID (not unique, identifying user)(column 10). the length of the data frame is about 750000 rows. I am trying to extract individual data frames (so getting a list or vector of data frames) split by the column containing the "user" identifier, to isolate the actions of a single actor.I have a data frame with 10 columns, collecting