Pandas zählen Werte nach Spalte
df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()
Grieving Goose
df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()
>>> df.set_index(["Person", "Single"]).count(level="Person")
Age
Person
John 2
Lewis 1
Myla 1