I've got a Message class with some useful method in it (let's say validate, get_correlation_id, whatever, ...).
This class has an init method with some required parameters (type, routing_key, etc...)
I've got a Param class that contains a validate_parameter method.
I've got a Status class that contains a validate_status method.
I've got a JobCreation class that inherits from Message and Param:
class JobCreation(Message, Param):
msg_type = 'osb.job.ask'
def __init__(self, parameters = {}, **kwargs):
# Process reply_to
reply_to = REPLY_TO_RESULTS
if 'reply_to' in kwargs:
reply_to = kwargs['reply_to']
del kwargs['reply_to']
# Init
super().__init__(type=self.msg_type, **kwargs, reply_to=reply_to)
self.parameters = parameters
def validate(self):
"""Validate the JobCreation"""
super().validate()
self.validate_parameters()
I've got a JobResult class that inherits from Message, Param and Status:
class JobResult(Message, Param, Status):
msg_type = 'osb.job.answer'
def __init__(self, status=None, parameters={}, **kwargs):
# Process routing_key
routing_key = ROUTING_KEY_STATUS
if 'routing_key' in kwargs:
routing_key = kwargs['routing_key']
del kwargs['routing_key']
# Init
super().__init__(type=self.msg_type, **kwargs, routing_key=ROUTING_KEY_STATUS)
self.status = status
self.parameters = parameters
def validate(self):
"""Validate the JobResult"""
super().validate()
self.validate_status()
self.validate_parameters()
And finally i've got a JobStatus class that inherits from Message and Status:
class JobStatus(Message, Status):
msg_type = 'osb.job.info'
def __init__(self, status=None, **kwargs):
# Process routing_key
routing_key = ROUTING_KEY_STATUS
if 'routing_key' in kwargs:
routing_key = kwargs['routing_key']
del kwargs['routing_key']
# Init
super().__init__(type=self.msg_type, **kwargs, routing_key=ROUTING_KEY_STATUS)
self.status = status
def validate(self):
"""Validate the JobStatus"""
super().validate()
self.validate_status()
As you can see, depending on the type of 'Job' initialized, I want to validate it but it could be a parameter validation, a status validation or both.
The problem is, in my unit tests, it raises an error like this :
class JobStatus(Message, Status):
TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases
I've tried to create a Base class inheriting from ABC (abstract base class), and make my Message, Status and Param classes inherit from Base - doesn't seem to work.
Do you know how can I fix it?
[EDIT] As asked, the minimal reproductible example:
class Message:
def __init__(self):
print('Message init')
def validate(self):
print('Message validation')
class Status:
def validate_status(self):
print('Status validation')
class Param:
def validate_parameters(self):
print('Parameters validation')
class JobCreation(Message, Param):
def __init__(self):
print('Jobcreation init')
super().__init__()
def validate(self):
super().validate()
class JobResult(Message, Param, Status):
def __init__(self):
print('Jobresult init')
super().__init__()
def validate(self):
super().validate()
self.validate_status()
self.validate_parameters()
class JobStatus(Message, Status):
def __init__(self):
print('Jobresult init')
super().__init__()
def validate(self):
super().validate()
self.validate_status()
if __name__ == "__main__":
job_creation = JobCreation()
job_creation.validate()
job_result = JobResult()
job_result.validate()
job_status = JobStatus()
job_status.validate()
