How to format datetime field in pandas - pandas

Question

I have the following dataframe:
xl_file
Out[2]:
Day Description
Date
2011-01-26 Wednesday Republic Day
2011-03-02 Wednesday Mahashivratri
2011-04-12 Tuesday Ram Navmi
2011-04-14 Thursday Dr. Babasaheb Ambedkar Jayanti
2011-04-22 Friday Good Friday
... ...
2020-05-25 Monday Id-Ul-Fitr (Ramzan ID)
2020-10-02 Friday Mahatma Gandhi Jayanti
2020-11-16 Monday Diwali-Balipratipada
2020-11-30 Monday Gurunanak Jayanti
2020-12-25 Friday Christmas
[144 rows x 2 columns]
To convert Day column to datetime field i used the following code:
xl_file['Day'] = pd.to_datetime(xl_file['Day'], format = '%A')
Where i specified the format however i am getting this:
xl_file
Out[4]:
Day Description
Date
2011-01-26 1900-01-01 Republic Day
2011-03-02 1900-01-01 Mahashivratri
2011-04-12 1900-01-01 Ram Navmi
2011-04-14 1900-01-01 Dr. Babasaheb Ambedkar Jayanti
2011-04-22 1900-01-01 Good Friday
... ...
2020-05-25 1900-01-01 Id-Ul-Fitr (Ramzan ID)
2020-10-02 1900-01-01 Mahatma Gandhi Jayanti
2020-11-16 1900-01-01 Diwali-Balipratipada
2020-11-30 1900-01-01 Gurunanak Jayanti
2020-12-25 1900-01-01 Christmas
[144 rows x 2 columns]
How can i change formatting so the datetime field shows day name.
I tried this:
xl_file['Day'].date.dayofweek
but that gives an error :AttributeError: 'Series' object has no attribute 'date'

Answer 1

You are trying to work with string text to go to date? The date is in the index. I'm not sure if you have that in datetime yet, but let's assume it's just a string. Convert the index to datetime (timestamp).
df.index = pd.to_datetime(df.index)
print(df)
Day
Date
2011-01-26 Wednesday
2011-03-02 Wednesday
2011-04-12 Tuesday
2011-04-14 Thursday
2011-04-22 Friday
2020-05-25 Monday
2020-10-02 Friday
2020-11-16 Monday
2020-11-30 Monday
2020-12-25 Friday
But the Day column is still just a string. We can get the name of the day from the date using day_name() and setting it to a column.
df["Day_Name"] = df.index.day_name()
print(df)
Day Day_Name
Date
2011-01-26 Wednesday Wednesday
2011-03-02 Wednesday Wednesday
2011-04-12 Tuesday Tuesday
2011-04-14 Thursday Thursday
2011-04-22 Friday Friday
2020-05-25 Monday Monday
2020-10-02 Friday Friday
2020-11-16 Monday Monday
2020-11-30 Monday Monday
2020-12-25 Friday Friday
If you want the index to have the days.
df.index = df.index.day_name()