如何为协议缓冲区Python中的嵌入消息字段赋值

Question

I have following proto and I am trying to assign a value to an embedded message field

message Foo {
  required Bar bar = 1;
}
message Bar {
  optional int32 i = 1;
} 

When I am writing following code in python, It gives below error

foo = Foo()
foo.bar.i = 1

Error:

AttributeError: 'instancemethod' object has no attribute 'i'

How to deal with this error?

Answer 1

To do what you want, in Python, you have to define the bar method within the Foo class. Something like this will do it:

class Foo:
    i = 1

    def bar(self):
        return self.i

if __name__ == '__main__':
    foo = Foo()
    foo.bar = 1
    print(foo.bar)  # this will print 1