import numpy as np 
import pandas as pd

a = np.arange(1000)

l = set([ f"{i:03d}" for i in a ])

sum_dict = dict()
print(len(l))
for i in l:
    _sum = sum(map(int, i))
    v = sum_dict.get(_sum, 0)
    sum_dict[_sum] = v + 1

df = pd.Series(sum_dict)
print(df.sort_values(ascending=False))