How can we add years to the current date?

Question

Good morning,
I am working on arcmap and I would like to set up a script that would allow me to add years.
I have a data arbres_ev which includes as field: date_diag (format_date), periodicity (integer) ,maj_previsional(format_date). the objective is to fill in the field maj_previsional whose value would correspond to: maj_previsional + periodicity therefore if periodicity=1 add one year...
I tested this script:
fields = ['date_diag','periodicity','maj_previsional']
#print(fields)
today = datetime.datetime(today.year, today.month, today.day)
with arcpy.da.UpdateCursor(inFeatures, fields) as cursor:
for the cursor line:
#print(str(row[1])
if ((str(row[0]) != ') and (str(row[1]) =='1'):
row[2] = arcpy.time.ParseDateTimeString(str(row[0])) + datetime.timedelta(days=365)
if ((str(row[0]) != ') and (str(row[1]) =='2'):
row[2] = arcpy.time.ParseDateTimeString(str(row[0])) + datetime.timedelta(days=730)
if ((str(row[0]) != ') and (str(row[1]) =='3'):
row[2] = arcpy.time.ParseDateTimeString(str(row[0])) + datetime.timedelta(days=1095)
if ((str(row[0]) != ') and (str(row[1]) ='4'):
row[2] = arcpy.time.ParseDateTimeString(str(row[0])) + datetime.timedelta(days=1460)
if ((str(row[0]) != ') and (str(row[1]) =='5'):
row[2] = arcpy.time.ParseDateTimeString(str(row[0])) + datetime.timedelta(days=1825)
cursor.updateRow(line)
print("Second part complete!")
So for a year it works but as soon as I spend the two years it doesn’t work.
can I use this function? If not, what function should I take?
thanking you for your help

blake.terhune · Answer

Your example code has a lot of syntax errors. If I'm interpreting it correctly, then something like this should work.

import arcpy
import datetime

fields = ['date_diag','periodicity','maj_previsional']
expression = "date_diag <> '' and date_diag is not null"
with arcpy.da.UpdateCursor(inFeatures, fields, expression) as cursor:
    for date_diag, periodicity, maj_previsional in cursor:
        if date_diag:
            maj_previsional = maj_previsional + datetime.timedelta(days = periodicity * 365)
            cursor.updateRow([date_diag, periodicity, maj_previsional])

If you need to account for leap year/day, then you'll have to update the date calculation.

Anonymous User · Answer

What error are you seeing? Simplifying your code for testing, the days seem to work ok: dte = datetime.datetime.now() row1 = dte + datetime.timedelta(days=365) row2 = dte + datetime.timedelta(days=730) row3 = dte + datetime.timedelta(days=1095) row4 = dte + datetime.timedelta(days=1460) row5 = dte + datetime.timedelta(days=1825) print(row1) print(row2) print(row3) print(row4) print(row5) 2024-03-27 08:51:39.793168 2025-03-27 08:51:39.793168 2026-03-27 08:51:39.793168 2027-03-27 08:51:39.793168 2028-03-26 08:51:39.793168 It would help of you formatted your code by clicking the ..., then to paste and format as python.