Get datetime objects in month range in Python.

demo.py

import calendar
import dataclasses
from datetime import datetime, timezone

@dataclasses.dataclass
class DatetimeRange:
    begin: datetime
    end: datetime

    @classmethod
    def month_range(cls, year, month, tzinfo=None):
        _, month_date_size = calendar.monthrange(year, month)
        return cls(
            begin=datetime.min.replace(year=year, month=month, day=1).astimezone(
                tzinfo
            ),
            end=datetime.max.replace(
                year=year, month=month, day=month_date_size
            ).astimezone(tzinfo),
        )


if __name__ == "__main__":
    dt_range = DatetimeRange.month_range(2021, 3)
    print(dt_range.begin, dt_range.end)
    # 2021-03-01 00:00:00+08:00 2021-03-31 23:59:59.999999+08:00