converting a pandas date to week number

Question

I would like to extract a week number from data in a pandas dataframe.

The date format is datetime64[ns]

I have normalized the date to remove the time from i

Answer 1

from datetime import date
df_date = pd.DataFrame([date.today()],columns  = ['today'])
print(df_date)
#### Print Output ####
#        today
#0  2019-09-07
df_date['weeknum'] = df_date.today.apply(lambda x:x.isocalendar()[1])
print(df_date)
#### Print Output ####
#        today  weeknum
#0  2019-09-07       36