将数组转换为Iron Python中的字符串

I am very, very new to Iron Phyton and I am trying to create a script that will allow a user to select the 'All' function in a drop down list. Here is the code that I have so far, but I get an error message saying that "The type 'System.String[]' of the property value does not match the expected 'System.String' type"I am very, very new to Iron Phyton and I am try