__cause__ A TracebackException of the original __cause__.

traceback.print_exc(limit=None, file=None, chain=True) This is a shorthand for print_exception(*sys.exc_info(), limit

@contextlib.contextmanager This function is a decorator that can be used to define a

'__main__' is the name of the scope in which top-level code executes. A module’s __name__ is set equal to '__main__' when read from standard input

sysconfig.get_config_var(name) Return the value of a single variable name. Equivalent to get_config_vars().get(name)

sys.getsizeof(object[, default]) Return the size of an object in bytes. The object can be any type of object. All built-in objects

sysconfig.get_config_vars(*args) With no arguments, return a dictionary of all configuration variables relevant for the current

@abc.abstractclassmethod A subclass of the built-in

format_exception_only() Format the exception part of the traceback. The return value is a generator

__subclasshook__(subclass) (Must be defined as a class method.) Check whether subclass