Python list of first day of month for given period

Question

I am trying find an efficient way of creating a list of dates only including the first day of the month for a given period. Something like this but better:

import datetime
dates = [
  datetime.date (2014, 4, 1),
  datetime.date (2014, 5, 1),
  datetime.date (2014, 6, 1),
  datetime.date (2014, 7, 1),
  datetime.date (2014, 8, 1),
  datetime.date (2014, 9, 1),
  datetime.date (2014, 10, 1),
  datetime.date (2014, 11, 1),
  datetime.date (2014, 12, 1),
  datetime.date (2015, 1, 1),
  datetime.date (2015, 2, 1)]

Alternatively, some direction on what to Google for this. Cheers!

Answer 1

With pandas :

   dates= pd.date_range('2018-01-01','2020-01-01' , freq='1M')-pd.offsets.MonthBegin(1)

result :

`DatetimeIndex(['2018-01-01', '2018-02-01', '2018-03-01', '2018-04-01',
               '2018-05-01', '2018-06-01', '2018-07-01', '2018-08-01',
               '2018-09-01', '2018-10-01', '2018-11-01', '2018-12-01',
               '2019-01-01', '2019-02-01', '2019-03-01', '2019-04-01',
               '2019-05-01', '2019-06-01', '2019-07-01', '2019-08-01',
               '2019-09-01', '2019-10-01', '2019-11-01', '2019-12-01'],
              dtype='datetime64[ns]', freq='MS')