Mock Datetime Object

mock_datetime_object.py

import datetime
import mock
 
real_datetime_class = datetime.datetime
 
 
def mock_datetime_now(target):
    """
    A mock patch context, we override the datetime.datetime with a custom value.
    """
 
    class DatetimeSubclassMeta(type):
        """Custom __instancecheck__ instance()"""
        @classmethod
        def __instancecheck__(mcs, obj):
            return isinstance(obj, real_datetime_class)
 
    class BaseMockedDatetime(real_datetime_class):
        @classmethod
        def today(cls):
            return target
 
    MockedDatetime = DatetimeSubclassMeta("datetime", (BaseMockedDatetime,), {})
    return mock.patch.object(datetime, "datetime", MockedDatetime)
 
# Example
today = datetime.datetime.today(2010, 1, 1)
with mock_datetime_now(today):
 print datetime.datetime.today()  # It prints 2010-1-1