Frozen date: freeze datetime.now at a known value for testing
pip install frozendate==0.1.4
Frozendate suspends time while your tests run.
Frozendate mocks datetime.datetime
and datetime.date
to provide known
times when testing.
import frozendate with frozendate.freeze(1999, 1, 1): party_like_its_1999() # freeze relative freezes time relative to the current date... with freeze_relative(days=-1): assert all_my_troubles_seemed_so_far_away() with freeze(1999, 12, 31): # ...or relative to the previous freeze with freeze_relative(days=1): print "happy new year!"
Normally time doesn't actually stop when you use freeze – it just starts again from the fixed point you specify, eg:
>>> import frozendate >>> import datetime >>> with frozendate.freeze(2000, 1, 1): ... print datetime.now().replace(microsecond=0) ... time.sleep(1) ... print datetime.now().replace(microsecond=0) ... 2000-01-01 00:00:00 2000-01-01 00:00:01
But you can always get the same value back if you pass hard=True
:
>>> with frozendate.freeze(2000, 1, 1, hard=True): ... print datetime.now().replace(microsecond=0) ... time.sleep(1) ... print datetime.now().replace(microsecond=0) ... 2000-01-01 00:00:00 2000-01-01 00:00:00
Instead of a context manager there are also regular patch and unpatch functions. These are useful in test case setup/teardown methods:
def setUp(self): frozendate.patch(2000, 1, 1) def tearDown(self): frozendate.unpatch()
When you call freeze or patch, it freezes time for all modules found in
sys.modules
.
Sometimes you want to restrict to a few named modules:
frozendate.freeze(modules=['mypackage.mymodule'])
Or patch everything, but exclude a few modules that need the real datetime still:
frozendate.freeze(dontpatch=['somemodule', 'someotherpackage'])