System.Collections.Generic lists in Python 'TypeError: type(s) expeected' error

Question

I am trying to run the following piece of code:

import clr
import sys
#import System.Collections
clr.AddReference("System.Collections")
from System.Collections.Generic import List
from System import String

class MyClass(object):
    def __init__(self, e=""):
        self.title = e


li = List[MyClass]()

list(li)

However, I am getting the error 'TypeError: type(s) expected' and cannot understand how to solve it.

This is related to System.Collections.Generic lists in Python

Thanks!

Answer 1

In Python.NET you can't use .NET lists to store Python objects in a strongly-typed way unless you do one of the following:

• derive your Python class from a .NET type

class MyClass(System.Object):
   # without __namespace__ - regular Python type
  __namespace__ = "MyNamespace"

• use List<System.Object> or List<Python.Runtime.PyObject>

• have a List<X> with a Python to .NET codec for the .NET type X