python - Pandas date_range to generate monthly data at beginning of the month -

i'm trying generate date range of monthly data day @ beginning of month:

pd.date_range(start='1/1/1980', end='11/1/1991', freq='m') 

this generates 1/31/1980, 2/29/1980, , on. instead, want 1/1/1980, 2/1/1980,...

i've seen other question ask generating data on specific day of month, answers saying wasn't possible, beginning of month surely must possible!

you can changing freq argument 'm' 'ms':

d = pandas.date_range(start='1/1/1980', end='11/1/1990', freq='ms')     print(d) 

this should print:

datetimeindex(['1980-01-01', '1980-02-01', '1980-03-01', '1980-04-01',                '1980-05-01', '1980-06-01', '1980-07-01', '1980-08-01',                '1980-09-01', '1980-10-01',                 ...                '1990-02-01', '1990-03-01', '1990-04-01', '1990-05-01',                '1990-06-01', '1990-07-01', '1990-08-01', '1990-09-01',                '1990-10-01', '1990-11-01'],               dtype='datetime64[ns]', length=131, freq='ms', tz=none) 

look offset aliases part of documentation. there states 'm' end of month (month end frequency) while 'ms' beginning (month start frequency).