Input DataFrame: rowsCount = 7, columnsCount = 5
nameagecityweightisHappy
firstNamelastName
AliceCooper15London54true
BobDylan45Dubai87true
CharlieDaniels20Moscownullfalse
CharlieChaplin40Milannulltrue
BobMarley30Tokyo68true
AliceWolf20null55false
CharlieByrd30Moscow90true

Output GroupBy
nameLengthgroup
11DataFrame 2 x 5
8DataFrame 1 x 5
14DataFrame 2 x 5
9DataFrame 2 x 5