[Ironpython-users] abstract class conversion?

Jeff Hardy jdhardy at gmail.com
Thu Dec 1 19:36:21 CET 2011

On Thu, Dec 1, 2011 at 10:14 AM, Michael Colonno <mcolonno at stanford.edu> wrote:
>             In VB.NET, this works just fine:
> Dim A As Type
> Dim Name As String
> Dim Option As Boolean
> Dim Err As Integer
> Dim value As Object
> value = A.function(Name, Option, Err)
>             In IronPython I am trying (pseudo-code):
> import clr
> clr.AddReferenceToFileAndPath("relevant dll")
> from API.Interop.whatever import Type
> A = Type()
> value = A.function("Name", True, err)
>             Two issues / questions:
> 1.     The IronPython code above produces: TypeError: Cannot create
> instances of Type because it is abstract. Why is an abstract Python class
> being created and do I have any control over this?

Calling `A = Type()` tries to create an instance of Type, which your
VB code doesn't do. Is `Type.function` a static method?

> 2.     Changing the code to access the functions of Type directly (e.g.
> Type.function()) results in a “self” argument being expressed as the first
> argument in the function. i.e. the syntax expected is now
> Type.function(self, string, boolean, int). I’m familiar with “self” only in
> the context of defining class functions and not outside of a class
> definition.

It really depends on how what the signature of the function is. If
it's static, calling `Type.function` from Python shouldn't need a self
argument. Can you find the signature of `Type.function` (ILSpy is your
friend here). Feel free to elide the names; they're not really

- Jeff

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