how to find all occurrences of an element in a list python code example

Example 1: get all indices of a value in list python

indices = [i for i, x in enumerate(my_list) if x == "whatever"]

Example 2: get all occurrence indices in list python

a_list = [1, 2, 3, 1]

indices = []
for i in range(len(a_list)):
   if a_list[i] == 1:
      indices.append(i)

# more concise way
a_list = [1, 2, 3, 1]
indices = [index for index, element in enumerate(a_list) if element == 1]

Example 3: 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 4: python count occurrences of an item in a list

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