FreezeGun: Let your Python tests travel through time ==================================
FreezeGun is a library that allows your python tests to travel through time by mocking the datetime module.
Once the decorator or context manager have been invoked, all calls to datetime.datetime.now(), datetime.datetime.utcnow(), and datetime.date.today() will return the time that has been frozen.
from freezegun import freeze_time
@freeze_time("2012-01-14")
def test():
assert datetime.datetime.now() == datetime.datetime(2012, 01, 14)
# Or class based
@freeze_time("2012-01-14")
class Tester(object):
def test_the_class(self):
assert datetime.datetime.now() == datetime.datetime(2012, 01, 14)from freezegun import freeze_time
def test():
assert datetime.datetime.now() != datetime.datetime(2012, 01, 14)
with freeze_time("2012-01-14"):
assert datetime.datetime.now() == datetime.datetime(2012, 01, 14)
assert datetime.datetime.now() != datetime.datetime(2012, 01, 14)from freezegun import freeze_time
freezer = freeze_time("2012-01-14 12:00:01")
freezer.start()
assert datetime.datetime.now() == datetime.datetime(2012, 01, 14, 12, 00, 01)
freezer.stop()from freezegun import freeze_time
@freeze_time("2012-01-14 03:21:34", tz_offset=-4)
def test():
assert datetime.datetime.utcnow() == datetime.datetime(2012, 01, 14, 03, 21, 34)
assert datetime.datetime.now() == datetime.datetime(2012, 01, 13, 23, 21, 34)
# datetime.date.today() uses local time
assert datetime.date.today() == datetime.datetime(2012, 01, 13)FreezeGun uses dateutil behind the scenes so you can have nice-looking datetimes
@freeze_time("Jan 14th, 2012")
def test_nice_datetime():
assert datetime.datetime.now() == datetime.datetime(2012, 01, 14)For the time being, if you use datetime as from datetime import datetime; now = datetime.now() then freezegun module must be imported before the datetime module is ever imported for this to work. If you use datetime as import datetime; now = datetime.datetime.now(), then you're good to go without worrying about import order.
To install FreezeGun, simply:
$ pip install freezegun