How to enforce datetime format (%Y-%m-%d %H:%M:%S) when the time is 00:00:00 when using pandas to_datetime() function?

Question

I have to save one record of a dataframe with a datetime column to a csv.The datetime column is in this %Y-%m-%d %H:%M:%S format.When the record has the following value in the date column eg: 2019-11-12 00:00:00 ,the value is saved as ' 2019-11-12 '.Is there a way to enforce the datetime format?

pandas version: 0.24.2

#eg 
d = {'run_date': ['2019-11-11 02:30:00','2019-11-12 00:00:00'], 'value': [40, 45]}

df = pd.DataFrame(data=d)
display(pd.to_datetime(df['run_date'],format='%Y-%m-%d %H:%M:%S')[-1:])

Answer 1

You can also specify the datetime format while saving to csv.

Please try df.iloc[-1:].to_csv("test_datetime_format.csv", index=False, date_format='%Y-%m-%d %H:%M:%S') and see if that works.

I've added .iloc[-1] to select the record you had issues with, but it should also work on the complete dataframe if you wish.

Regards, Koen