I am working on python2 environment (codes for legacy softwares) and I do not have access to numpy and pandas. I stumbled with a problem:

How to sort datetiems using month and days only (not the year, it’s for birthdates where only month and day matters).

My attempt

from datetime import date

lst = [date(2021,1,10), date(2020,3,1), date(2020,2,2), date(2020,2,1),date(2020,1,10)]

lst = sorted(lst)
print(lst)

[datetime.date(2020, 1, 10),
 datetime.date(2020, 2, 1),
 datetime.date(2020, 2, 2),
 datetime.date(2020, 3, 1),
 datetime.date(2021, 1, 10)]

Required

[datetime.date(2020, 1, 10),
 datetime.date(2021, 1, 10)
 datetime.date(2020, 2, 1),
 datetime.date(2020, 2, 2),
 datetime.date(2020, 3, 1),
 
]

>Solution :

you have to define a sorting key

sorted(lst, key=lambda x: (x.month, x.day))