from types import ModuleType
class MyModule(ModuleType):
def __metamodule_init__(self):
self._metamodule_init_called = True
class_attr = "foo"
import metamodule
metamodule.install(__name__, MyModule)
del metamodule
other_attr = "bar"
import metamodule
metamodule.install(__name__)
del metamodule
__warn_on_access__["a"] = (
1,
FutureWarning("'a' attribute will become 2 in next release"))
# Setup the metamodule.
import metamodule
metamodule.install(__name__)
del metamodule
# Automatically execute "import .submodule" the first time that someone tries
# to access it:
__auto_import__.add("submodule")
# Issue a warning whenever "a" is accessed.
# We use a FutureWarning so that it's easier to see from the REPL that the
# warning is issued.
__warn_on_access__["a"] = (
1,
FutureWarning("'a' attribute will become 2 in next release"))
# Regular globals are still exposed and accessible with no speed penalty:
b = 2
def f(x):
return b * x
from types import ModuleType
class MyModule(ModuleType):
# Make sure that having no __metamodule_init__ is legal, and does not get
# routed through __getattr__.
def __getattr__(self, attr):
if attr == "class_attr":
return "foo"
raise AttributeError
import metamodule
metamodule.install(__name__, MyModule)
del metamodule
other_attr = "bar"
