Python - Code returns dates but when added to list the format changes

Question

I am trying to create a list of dates to add to a Pandas dataframe as a new column using ...

df['Surveys_Last_Week'] = list

I have done this before without issues. However, with the code below I get the dates returned in the format I want but when I add them to a list the format changes and they become prefixed with datetime.date

2022-05-14
2022-07-09
2022-03-05
2022-03-12

[datetime.date(2022, 5, 14), datetime.date(2022, 7, 9), datetime.date(2022, 3, 5), datetime.date(2022, 3, 12)]

How can I get the dates into a list in the format that they return in?

The code I am using is as follows ...

today = datetime.date.today()

completion_list_80 = []

for value in df.Weeks_to_80pc:
    if value == float('inf'):
        pass
    else:
        remaining_weeks = datetime.timedelta(weeks=value)
        projected_completion = today + remaining_weeks
        print(projected_completion)
        completion_list_80.append(projected_completion)
                                     
print(completion_list_80)

Any help very much appreciated.

Thank you

Answer 1

To convert the list of datetime.date objects to a pandas.DatetimeIndex column using NumPy's datetime64 dtype, you can wrap pandas.to_datetime() around your list when you insert it into your DataFrame:

df['Surveys_Last_Week'] = pd.to_datetime(completion_list_80)

Alternatively, to convert the datetime.date objects to their yyy-mm-dd string representations, you can format them with strftime as you append them to the list (however, I would recommend sticking to pandas' builtin DatetimeIndex support):

completion_list_80.append(projected_completion.strftime('%Y-%m-%d'))