Pyro4返回POD对象后访问属性报错，如何直接使用其字段？

Ah, I see the issue here! The problem is that even though you've marked your POD class with @Pyro4.expose, Pyro4 doesn't automatically expose instance attributes like self.a by default. The class-level @expose decorator only makes methods accessible remotely, not direct attribute access.

Let's go through two straightforward fixes for this:

Solution 1: Expose attributes using properties #

The cleanest way to expose your a attribute is to wrap it in a @property decorator and ensure that property is exposed. This gives you control over what's accessible and allows you to add logic later if needed:

import Pyro4

@Pyro4.expose
class POD:
    def __init__(self):
        self._a = 1  # Use a private backing variable
    
    @property
    @Pyro4.expose  # Expose the property getter
    def a(self):
        return self._a

@Pyro4.expose
class Source:
    def get(self):
        p = POD()
        daemon.register(p)
        return p

daemon = Pyro4.daemon()
ns = Pyro4.locateNS()
uri = daemon.register(Source)
ns.register('test_obj', uri)
daemon.requestLoop()

Now when you access o.a in your client code, it will call the exposed property getter method behind the scenes, which Pyro4 recognizes as an exposed method.

Solution 2: Enable automatic attribute exposure #

If you want all instance attributes of your exposed classes to be accessible remotely without writing properties, you can enable Pyro4's EXPOSE_ATTRIBUTES configuration option. This is a quicker approach but be careful—it will expose all attributes, including any you might not intend to make public:

Add this line at the top of your server code:

Pyro4.config.EXPOSE_ATTRIBUTES = True

Your original POD class will work as-is with this setting. Pyro4 will automatically handle attribute access for any class marked with @Pyro4.expose.

Testing the fix #

Either way, your client code should now work without throwing that error:

import Pyro4
s = Pyro4.Proxy('PYRONAME:test_obj')
o = s.get()
print(o.a)  # This will output 1 as expected!

Just a quick note: When returning the POD instance from Source.get(), calling daemon.register(p) is actually optional—Pyro4 will automatically register exposed objects returned from remote methods. But keeping it in doesn't hurt anything.

内容的提问来源于stack exchange，提问作者Tom