A significant part of the EasyOPC Extensions for .NET functionality is provided in form of so-called Extension Methods. In languages that support them (including C#, VB.NET), extension methods will appear as additional methods on the classes that are being extended. For example, the  EasyDAClient class appears as having many more new methods that you can choose from. This way, you can write a code that call e.g. GetDataTypePropertyValue (extension) method on the EasyDAClient object, although the method is actually located in the  IEasyDAClientExtension2 class which you do not even have to be aware of.

In languages that do not support extension method syntax, it is still possible to use them, but they need to be called as static method on the extension class, and you provide the object reference as an additional argument. In the above example, you would call IEasyDAClientExtension2.GetDataTypePropertyValue instead, and pass it the EasyDAClient object as the first argument.

For calling extension methods in Python, see Programming in Python.