Suddenly I had to need this.
This script can get the duplicate number of each element in array at Python. In this script, the duplicate number of each element is obtained and sorted by the duplicate number. This was expressed by the comprehension.
data = ['a', 'b', 'c', 'd', 'b', 'c', 'd', 'b', 'c', 'b']
result = sorted({i: data.count(i) for i in set(data)}.items(), key=lambda x: x[1], reverse=True)
print(result)
>>> [('b', 4), ('c', 3), ('d', 2), ('a', 1)]