twisted.python.

def passthru(arg):

Return arg. Do nothing.

Parameters	arg	The arg to return.
Returns	`arg`

def _ensureOldClass(cls):

Ensure that cls is an old-style class.

Parameters	cls	The class to check.
Returns	The class, if it is an old-style class.
Raises	`ValueError` if it is a new-style class.

@_replaceIf(_PY3, passthru)
@_replaceIf(_shouldEnableNewStyle(), _ensureOldClass)
def _oldStyle(cls):

A decorator which conditionally converts old-style classes to new-style classes. If it is Python 3, or if the TWISTED_NEWSTYLE environment variable has a falsey (no, false, False, or 0) value in the environment, this decorator is a no-op.

Parameters	cls	An old-style class to convert to new-style. (type: `types.ClassType`)
Returns	A new-style version of `cls`.

Function	passthru	Return `arg`. Do nothing.
Function	_ensureOldClass	Ensure that `cls` is an old-style class.
Function	_oldStyle	No summary

twisted.python._oldstyle module documentation

`twisted.python._oldstyle` module documentation