change multiple properties on setter with singleton

singleton_property_setter.py

import functools

def singleton(cls, *args, **kw):
    instances = dict()
    @functools.wraps(cls)
    def _fun():
        if cls not in instances:
            instances[cls] = cls(*args, **kw)
        return instances[cls]
    return _fun

@singleton
class A(object):
    def __init__(self):
        self._fds = False
        self.path = 'path/'

    @property
    def fds(self):
        return self._fds
    
    @fds.setter
    def fds(self, fds):
        self._fds = fds
        self.path = '/fds/path' if self._fds else 'path'

print(A().path)
A().fds = True
print(A().path)


class B(object):
    _fds = False
    def __init__(self):
        self.path = '/fds/path' if self._fds else 'path'


print(B().path)
B._fds = True
print(B().path)

@singleton
class C(object):
    _fds = False
    def __init__(self):
        self.path = '/fds/path' if self._fds else 'path'


# print(C().path)
C._fds = True # can be only initialized once
print(C().path)