Datetime（TypeError：strptime() 参数 1 必须是 str，而不是 Timestamp）

Question

I want add new column 'order_month' from column 'order_date'

The code is:

import datetime
import pandas as pd
dataset = pd.read_excel("D:\\DataSciencePython/retail_raw_reduced.xltx")
dataset['order_month'] = dataset['order_date'].apply(lambda x: datetime.datetime.strptime(x, "%Y-%m-%d").strftime('%Y-%m'))
print(dataset.head())

The output should be:

   order_id  order_date  customer_id  ... quantity item_price order_month
0   1703458  2019-10-17        14004  ...       10     740000     2019-10
1   1706815  2019-10-24        17220  ...        2     604000     2019-10
2   1710718  2019-11-03        16518  ...        8    1045000     2019-11
3   1683592  2019-08-19        16364  ...        4     205000     2019-08
4   1702573  2019-10-16        15696  ...        2    4475000     2019-10

But i found error:

PS D:\DataSciencePython> & C:/Users/SCZ/AppData/Local/Programs/Python/Python38/python.exe 
"d:/DataSciencePython/Data Visualization 1/menambahkolommonth.py"
Traceback (most recent call last):
File "d:/DataSciencePython/Data Visualization 1/menambahkolommonth.py", line 4, in <module>
dataset['order_month'] = dataset['order_date'].apply(lambda x: datetime.datetime.strptime(x, "%Y-%m-%d").strftime('%Y-%m'))
File "C:\Users\SCZ\AppData\Local\Programs\Python\Python38\lib\site-packages\pandas\core\series.py", line 4433, in apply
return SeriesApply(self, func, convert_dtype, args, kwargs).apply()
File "C:\Users\SCZ\AppData\Local\Programs\Python\Python38\lib\site-packages\pandas\core\apply.py", line 1088, in apply
return self.apply_standard()
File "C:\Users\SCZ\AppData\Local\Programs\Python\Python38\lib\site-packages\pandas\core\apply.py", line 1143, in apply_standard
mapped = lib.map_infer(
File "pandas\_libs\lib.pyx", line 2870, in pandas._libs.lib.map_infer
File "d:/DataSciencePython/Data Visualization 1/menambahkolommonth.py", line 4, in <lambda>
dataset['order_month'] = dataset['order_date'].apply(lambda x: datetime.datetime.strptime(x, "%Y-%m-%d").strftime('%Y-%m'))
TypeError: strptime() argument 1 must be str, not Timestamp

Please help me. Thankyou!

Answer 1

Can you run dataset.dtypes ? You can check if order_date is already a datetime object. If it is, then you don't need to datetime.datetime.strptime(x, "%Y-%m-%d")