我怎样才能从机器人框架中的python类中获取self对象

Question

Engine.py will import several classes as self object

Engine.py

from api import api
from cloud import cloud
class Engine(object):
    def __init__(self, env):
        session = dict()
        self.api = api.API(session)
        self.cloud= cloud.CLOUD(session)

api.py

class API(object):
    def __init__(self, session):
        self.session = session

    def api_keyword(self):
        return SOMETHING

My question is :

How can I use the keyword under api.py and cloud.py and ONLY import Engine.py into robot file

test.robot

*** Settings ***
Library         Engine.py  ${env}


*** Test Cases ***
python class test
    [Tags]    class
    Engine.api.api_keyword

And I got error message:

No keyword with name 'Engine.api.api_keyword' found.

Answer 1

Robot Framework maps only class methods to keywords; your class Engine does not expose any methods from api and cloud - it probably uses them internally, but doesn't define any as its own.
So here's your first solution - create wrapper methods for all you need in the cases:

def an_api_method(self):
    self.api.something()

And now you'll have the An API Method keyword at your disposal in the cases.

---

Solution two - make your class inherit the other two:

class Engine(api, cloud):

, and your cases will have access to all their public methods.
This one is more involving - you'll have to call their constructors (with super() ), and if you maintain a state in your class, you'll have to accommodate for that. Ie more drastic code changes are needed.

---

The third solution doesn't require any changes to the Enhine code - but, disclaimer: I don't know will it work :) (I'm not at a computer).
It consists of two calls - first to use Get Library Instance to get the object of your imported library (from the Builtin library), and then - Call Method :

${ref}=     Get Library Instance    Engine
Call Method     $ref.api    api_keyword