Can'；在Python中找不到聚合结果列

“计数”列在哪里？

我想您正在寻找

值\u计数

s = pd.Series(["08-10-2017", "08-10-2017", "08-10-2017", "09-10-2017", "09-10-2017", "09-10-2017", "10-10-2017", "10-10-2017", "10-10-2017", "11-10-2017", "11-10-2017", "11-10-2017", "12-10-2017", "12-10-2017", "12-10-2017", "13-10-2017", "13-10-2017", "13-10-2017", "14-10-2017", "14-10-2017"])
p = pd.DataFrame(data=s)
p.columns = ['date']
p.groupby('date').agg('count').reset_index().columns

如果你想和groupby打交道

p.date.value_counts()
Out[1095]: 
09-10-2017    3
13-10-2017    3
10-10-2017    3
12-10-2017    3
08-10-2017    3
11-10-2017    3
14-10-2017    2
Name: date, dtype: int64

如果你想使用count

p.groupby('date').size()

---

你能把你得到的结果加起来吗？

p.groupby('date').agg({'date':'count'})
Out[1101]: 
            date
date            
08-10-2017     3
09-10-2017     3
10-10-2017     3
11-10-2017     3
12-10-2017     3
13-10-2017     3
14-10-2017     2