Generated constructors incorrectly accept positional arguments

The annotated __init__ method generated for a protobuf message accepts positional arguments, but the underlying implementation accepts only named arguments. The first parameter after self should be a nameless * parameter. This will tell mypy and other type checkers that positional arguments are not allowed when calling the constructor.

For example, a protobuf message with a string: name field will generate the following annotated stub:

class MyMessage(google___protobuf___message___Message):
    name = ... # type: typing___Text

    def __init__(self,
        name : typing___Optional[typing___Text] = None) -> None: ...

If callers attempt to construct this message by calling MyMessage('bob'), a runtime error occurs indicating that positional arguments are not allowed for this call.

To match the underlying implementation, it should be:

    def __init__(self, *,
        name : typing___Optional[typing___Text] = None) -> None: ...

[nipunn1313]

This generated constructors issue should be fixed with #74.

The virtualenvironment issue was quite interesting and should be fixed with #76. Didn’t actually have to do with py2/py3, but rather with google’s new release of the python library python-protobuf (this project didn’t pin the version!). My setup continued to work because I still had the old version installed.

[erictraut]

Thanks! Much appreciated.