笔者再看DSSD的过程中，发现原来dict还可以这样扩展，特此记录一下。
单纯的摘选涉及到dict扩展的内容：
def _register_generic(module_dict, module_name, module):
assert module_name not in module_dict
module_dict[module_name] = module
class Registry(dict):
"""
A helper class for managing registering modules, it extends a dictionary
and provides a register functions.
Eg. creating a registry:
some_registry = Registry({"default": default_module})
There‘re two ways of registering new modules:
1): normal way is just calling register function:
def foo():
...
some_registry.register("foo_module", foo)
2): used as decorator when declaring the module:
@some_registry.register("foo_module")
@some_registry.register("foo_module_nickname")
def foo():
...
Access of module is just like using a dictionary, eg:
f = some_registry["foo_module"]
"""
def __init__(self, *args, **kwargs):
super(Registry, self).__init__(*args, **kwargs)
def register(self, module_name, module=None):
# used as function call
if module is not None:
_register_generic(self, module_name, module)
return
# used as decorator
def register_fn(fn):
_register_generic(self, module_name, fn)
return fn
return register_fn
其实fn代表添加的model list，这里我才用添加匿名函数作为示例：
# Eg. creating a registry:
some_registry = Registry({"default": lambda x:x*2})
print(some_registry)
some_registry.register("foo_module", lambda x:x*3)
print(some_registry)
@some_registry.register("foo_module_nickname")
def foo(x):
return x*4
print(some_registry)
print(some_registry["default"](3))
原文：https://www.cnblogs.com/a-runner/p/14851198.html