count how many times an element appears in a list python code example

Example 1: count how many times a value shows in python list

#use count():
>>> my_list = [1, 2, 3, 1, 4]
>>> print(my_list.count(1))
2

#OR, you can also use counter:
>>> from collections import Counter
>>> z = ['blue', 'red', 'blue', 'yellow', 'blue', 'red']
>>> Counter(z)
Counter({'blue': 3, 'red': 2, 'yellow': 1})

Example 2: python find number of occurrences in list

student_grades = [9.1, 8.8, 10.0, 7.7, 6.8, 8.0, 10.0, 8.1, 10.0, 9.9]

samebnumber = student_grades.count(10.0)

print(samebnumber)

Example 3: count occurrence in array python

arr = np.array( [1, 2, 3, 2, 1, 2])
occ = np.count_nonzero(arr==0)
print(occ)
0
occ = np.count_nonzero(arr==1)
print(occ)
2