In Python: `date` vs `datetime` object

In Python, date and datetime are classes provided by the datetime module for handling dates and times.

1. Difference Between date and datetime Objects:

date Object:
Represents a calendar date (year, month, and day) without any time-of-day information.
Example:

from datetime import date

d = date.today()  # Gets the current date
print(d)  # Output will be something like 2023-10-04

datetime Object:
Represents a specific moment in time, including both the date and the time (year, month, day, hour, minute, second, microsecond).
Example:

from datetime import datetime

dt = datetime.now()  # Gets the current date and time
print(dt)  # Output will be something like 2023-10-04 15:06:00.123456

In summary, use date to represent dates without time, and datetime to represent a specific point in time inclusive of both date and time.

1. Checking Object Type: To check the type of an object, you can use the built-in type() function or the isinstance() function.

Using type():

from datetime import date, datetime

some_date = date.today()
some_datetime = datetime.now()

print(type(some_date))      # <class 'datetime.date'>
print(type(some_datetime))  # <class 'datetime.datetime'>

Using isinstance():

from datetime import date, datetime

some_date = date.today()
some_datetime = datetime.now()

print(isinstance(some_date, date))         # True
print(isinstance(some_date, datetime))     # False
print(isinstance(some_datetime, date))     # False
print(isinstance(some_datetime, datetime)) # True

Using isinstance() is usually preferred, especially when dealing with inheritance, because it considers subclasses and provides a more flexible and safe way to check types.

To apply this in the context you provided:

from datetime import date, datetime

# Assuming period.upper is the attribute you want to check
if isinstance(period.upper, date) and not isinstance(period.upper, datetime):
    current_date = date.today()
else:
    current_date = datetime.now()

This way, you ensure that current_date uses date.today() if period.upper is a date object, and timezone.now() otherwise (if it was a datetime object).