IDE incorrectly reports unexpected arguments to data class instance




I am using data classes with inheritance following the ideas of this SO post: (see top answer).  

I have 5 classes.  One abstract class (abc.ABC), three parent data classes, and one child class.

The editor believes the child class has no arguments in its __init__ and gives me a warning in the code.  However, the Python console will happily show that the child class does have arguments in its constructor with the CMD+P command (on Mac).  

The class hierarchy works like this:


class _AbstractFields:

   data: bytes = None

class AbstractParent:



class _ChildFields

  name: str


class _ChildBase(_AbstractFields, _ChildFields):



Child(_ChildBase, AbstractParent):



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It should be fixed in scope of in 2019.1

You can try our EAP build if you like.

Please note, that you can have multiple PyCharm installations at the same time. So you don't need to uninstall current stable version to install EAP build.


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