code: import csv
  import pandas as pd
  from tqdm import tqdm
  from collections import Counter
  dbRead = open('db.csv', "r", newline='', encoding='utf8')
  db = list(csv.reader(dbRead, delimiter=","))
  column = [row[-1] for row in db]
  for row in tqdm(db):
      row[-2]=Counter(column)[row[-1]]
  df=pd.DataFrame(data=db)
  df.to_csv('db.csv', sep=",", encoding='utf8')
apis: pandas.DataFrame