Professional IronPython

Creating a Reference to .NET Assemblies
Not every .NET assembly is available to IronPython by default, even if that assembly appears in the 
Global Assembly Cache (GAC). As with any other .NET language, you sometimes need to reference 
.NET assemblies in order to import and use them. For example, try typing
from System.Xml import *
and press Enter. You get an error message as output stating the following:
from System.Xml import *
Traceback (most recent call last):
File “”, line 1, in
ImportError: No module named Xml
FIguRE 7-6: 
Modify the buffer to hold more
lines of information.
FIguRE 7-7: 
Choose a configuration
change option that matches your
.NET usage habits.
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CHAPTER 7
Accessing the .net FrAmework
FIguRE 7-8: 
The screen buffer is now large enough to hold the help information you need.
Of course, you know that the 
System.Xml
assembly does exist. This error message tells you that you 
have to add a reference to the 
System.Xml
assembly before you can use it. In order to add a reference, 
you must import the 
clr
(Common Language Runtime) module. You can then use one of the five
following methods to import the assembly.
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clr.AddReference(
AssemblyObjectOrFilename
)
: Adds a reference to the .NET assem-
bly by passing an assembly object directly or by specifying the assembly filename. (You can 
provide either a partial or full filename.) This is a generic sort of assembly reference addition 
because you don’t have control over which assembly version IronPython loads. You can use 
this method when you’re experimenting and really don’t care about which version of the .NET 
assembly you get. This is also a good method to use when you’re not sure which version of the 
assembly the user has installed on his or her machine but do know that all versions of the .NET 
Framework include the functionality you require. 
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