pythonnet cannot call method from vb .net dll - TypeError

Question

we are establishing connection from python to .net VB code. We successfully created DLL in VB, and we can import it to python using CLR. The class from DLL is imported and all the methods are visible. However when we call a method we fail with TypeErrors - even method with no arguments fails. PS. The other (standard) VB methods work fine (i.e. from System import String a=String("Some string")) PS2. The code written in C# also works fine with this method

Python code to connect with .dll:

#!/usr/bin/env python
# -*- coding: iso-8859-15 -*-    
    import os,sys
    import site
    scriptPath=r"E:\Dropbox\SISTeMA\TRE development\TRE Add-In\visum\Visum_VB_interactions\From PTV\VisumNetAddIn\32Bit"
    assemblyPath=r"E:\Dropbox\SISTeMA\TRE development\TRE Add-In\visum\Visum_VB_interactions\Interact\bin\Debug\Interact.dll"
    site.addsitedir(scriptPath)
    import clr
    import System
    assemblyPath = os.path.join(scriptPath,assemblyPath)
    site.addsitedir(os.path.dirname(assemblyPath))
    assemblyFile,extension  = os.path.splitext(os.path.basename(assemblyPath))
    clr.AddReference(assemblyFile)   
    from Interact import Interact_Class

VB .net class compiled to dll:

Imports System
Public Class Interact_Class
    Public s As String

    Public Sub give_me()
        s = "got it"
    End Sub

    Public Sub give_me_sth(ByVal sth As String)
        s = sth
    End Sub

    Public Function I_will_give_you() As String
        Return "Here You go"
    End Function
End Class

Python calls:

from Interact import Interact_Class
print Interact_Class.give_me
Interact_Class.give_me()
from System import String
s=String("I will give You")
print Interact_Class.give_me_sth(s)
print Interact_Class.I_will_give_you()

The resulting errors:

Interact_Class.give_me()
TypeError: not enough arguments

print Interact_Class.give_me_sth(s)
TypeError: No method matches given arguments

print Interact_Class.I_will_give_you()
TypeError: not enough arguments

Thanks a lot!

Answer 1

In your Python code, you are using the VB class as though it is a static class in C# terms, or a module in VB.Net terms.

You need to create an instance of it in python and then call the methods on the instance, not the class definition.