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

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

detach() If self is alive then mark it as dead and return the tuple (obj, func, args, kwargs). If self

array.insert(i, x) Insert a new item with value x in the array before position i. Negative values are treated

weakref.proxy(object[, callback]) Return a proxy to object which uses a weak reference. This supports use of the proxy

types.DynamicClassAttribute(fget=None, fset=None, fdel=None, doc=None) Route attribute access on a class to __getattr__.

date.isocalendar() Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The ISO calendar

class collections.abc.Container class collections.abc.Hashable class collections.abc.Sized

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