我有一个Dataframe train_data_new，其中有一个pick_datetime列，我只是从中提取日期部分：
train_data_new['pickup_datetime'] = pd.to_datetime(train_data_new.pickup_datetime)
train_data_new['pickup_date'] = train_data_new['pickup_datetime'].dt.date
train_data_new.reset_index(inplace = True)
接下来，我创建了另一个数据框，该数据框按Pickup_date分组乘车： 我正在尝试使用tsplot可视化此信息：
vendor_date = pd.DataFrame(train_data_new.groupby(['vendor_id','pickup_date'])['id'].count())
vendor_date.reset_index(inplace = True)
vendor_date['unit'] = 1
sns.tsplot(data = vendor_date, time = "pickup_date", value = 'id', unit = 'vendor_id', condition = "vendor_id")
vendor_id pickup_date id unit
0 1 2016-01-01 3048 1
1 1 2016-01-02 2887 1
2 1 2016-01-03 2895 1
3 1 2016-01-04 3164 1
4 1 2016-01-05 3304 1
5 1 2016-01-06 3412 1
6 1 2016-01-07 3607 1
但是我得到一个错误：TypeError：float（）参数必须是字符串或数字，而不是'datetime.date'
我在这里做错了什么？请提出建议！谢谢