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Implement IConvertible on PyObject by filmor · Pull Request #1762 · pythonnet/pythonnet

@filmor

What does this implement/fix? Explain your changes.

Implements the IConvertible interface for PyObject instances.

Does this close any currently open issues?

Should fix #1755.

Any other comments?

...

Checklist

Check all those that are applicable and complete.

  • Make sure to include one or more tests for your change
  • If an enhancement PR, please create docs and at best an example
  • Ensure you have signed the .NET Foundation CLA
  • Add yourself to AUTHORS
  • Updated the CHANGELOG

@filmor

@lostmsu

@lostmsu

@filmor

It doesn't look like there is an alternative yet, though, right? And I also don't think that they are actually going to drop the interface, they are just not extending it for new primitive types, which have no representation in Python anyway.

@lostmsu

@filmor the new Half type does not implement IConvertible though it is nearly identical to Single and Double. So I guess it is kinda deprecated (not that I completely agree with everything .NET team does).

lostmsu

return ToBigInteger().ToString(format, formatProvider);
}

public override TypeCode GetTypeCode() => TypeCode.Int64;

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Generally, this is wrong.

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The docs are a bit unclear on this function. I used this as an "should almost always work" value, the InvalidCastException might still be thrown if the conversion fails. We could drop the GetTypeCode overrides entirely and just return TypeCode.Object if you'd prefer that.

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I can't say for others, just for this one. Honestly, not sure if anyone ever uses this. Our own code assumes TypeCode.Int64 refers to System.Int64, so removing might be a good idea.

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I'm not sure I follow. GetTypeCode is supposed to be a hint that allows you to write a switch like

switch (convertible.GetTypeCode()) {
    case TypeCode.Int64:
        return Convert.ToInt64(convertible);
}

It doesn't mean that the object is a System.Int64 already.

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You seem to be correct on that. Still not sure Int64 is valid for this specific case, but float and string probably are. I am fine either way though. I don't think we will get people complaining about this returning Int64 any time soon.