def count_num(my_list, x_val):
    my_counter = 0
    for elem in my_list:
        if (elem == x_val):
            my_counter = my_counter + 1
    return my_counter

my_list = [ 66, 26, 48, 140, 66, 20, 1, 96, 86]
print("The list is :")
print(my_list)
occ_number = 66
print('{} 出现了 {} 次'.format(occ_number, count_num(my_list, occ_number)))

The list is :
[66, 26, 48, 140, 66, 20, 1, 96, 86]
66 出现了 2 次