import pandas as pd nowcoder = pd.read_csv("nowcoder.csv", parse_dates=["date"]) nowcoder = nowcoder.set_index("date") nowcoder.dropna() # daily_num = nowcoder.groupby(nowcoder.index.date)['question_id'].count() # print(daily_num) daily_num = nowcoder["question_id"].resample("D").nunique() print(daily_num)