calendar.isleap(year) Returns

classmethod datetime.now(tz=None) Return the current local date and time. If optional argument tz is None

date.replace(year, month, day) Return a date with the same value, except for those parameters given new values by whichever

class weakref.ref(object[, callback]) Return a weak reference to object. The original object can be retrieved by calling

formatyear(theyear, width=3) Return a year’s calendar as an HTML table. width (defaulting to 3) specifies the number

alive Property which is true if the finalizer is alive, false otherwise.

time.min The earliest representable time, time(0, 0, 0, 0).

class weakref.WeakValueDictionary([dict]) Mapping class that references values weakly. Entries in the dictionary will be discarded

class collections.UserString([sequence]) Class that simulates a string or a Unicode string object. The instance’s content is

class weakref.WeakSet([elements]) Set class that keeps weak references to its elements. An element will be discarded when no