CODEWITHSUNDEEP
pythonpython-3.xpandas
RustyShackleford
RustyShackleford

Reputation: 3667

How to generate random dates between date range inside pandas column?

I have df that looks like this

df:

id   dob
1    7/31/2018
2    6/1992

I want to generate 88799 random dates to go into column dob in the dataframe, between the dates of 1960-01-01 to 1990-12-31 while keeping the format mm/dd/yyyy no time stamp.

How would I do this?

I tried:

date1 = (1960,01,01)
date2 = (1990,12,31)

for i range(date1,date2):
    df.dob = i

Upvotes: 1

Views: 3012

Answers (1)

sacuL
sacuL

Reputation: 51335

I would figure out how many days are in your date range, then select 88799 random integers in that range, and finally add that as a timedelta with unit='d' to your minimum date:

min_date = pd.to_datetime('1960-01-01')
max_date = pd.to_datetime('1990-12-31')

d = (max_date - min_date).days + 1

df['dob'] = min_date + pd.to_timedelta(pd.np.random.randint(d,size=88799), unit='d')

>>> df.head()
         dob
0 1963-03-05
1 1973-06-07
2 1970-08-24
3 1970-05-03
4 1971-07-03

>>> df.tail()
             dob
88794 1965-12-10
88795 1968-08-09
88796 1988-04-29
88797 1971-07-27
88798 1980-08-03

EDIT You can format your dates using .strftime('%m/%d/%Y'), but note that this will slow down the execution significantly:

df['dob'] = (min_date + pd.to_timedelta(pd.np.random.randint(d,size=88799), unit='d')).strftime('%m/%d/%Y')

>>> df.head()
          dob
0  02/26/1969
1  04/09/1963
2  08/29/1984
3  02/12/1961
4  08/02/1988
>>> df.tail()
              dob
88794  02/13/1968
88795  02/05/1982
88796  07/03/1964
88797  06/11/1976
88798  11/17/1965

Upvotes: 8

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