python count occurrences of an item in a list

1>>> l = ["a","b","b"]
2>>> l.count("a")

1student_grades = [9.1, 8.8, 10.0, 7.7, 6.8, 8.0, 10.0, 8.1, 10.0, 9.9]
2
3samebnumber = student_grades.count(10.0)
4
5print(samebnumber)

1>>> [1, 2, 3, 4, 1, 4, 1].count(1)
23