Pandas - 月年格式的两个日期之间的月数

Question

I have dates in format of Jan-09, Jan-18 where 09 and 18 are years. How do I code to find the number of months between these two days. I tried using this code:

ata4['mob_try'] = ((data4.last_pymnt_date - data4.issue_date)/np.timedelta64(1, 'M')).

data4['mob'] = data4['mob_try'].astype(int)

but there is an error "unsupported operand type(s) for -: 'str' and 'str'" how do I resolve this??

Answer 1

You can use datetime and relativedelta to achieve this:

from datetime import datetime
from dateutil import relativedelta
date1 = datetime.strptime(str('Jan-09'), '%b-%y')
date2 = datetime.strptime(str('Jan-18'), '%b-%y')
r = relativedelta.relativedelta(date2, date1)

total_months = r.years*12 + r.months

print("Total months: {0}".format(total_months))

Answer 2

On which line this error occurs? If it's on the 1st line, maybe last_pymnt_date or issue_date columns are still stored as int . In this case, you must use pd.to_datetime() on each one first.

This example should work:

d1 = pd.to_datetime(data4.last_pymnt_date)

d2 = pd.to_datetime(data4.issue_date)

data4['mob'] = (d1 - d2) // np.timedelta64(1, 'M'))