Core Python Programming (2nd Edition)

23.2. Programming Microsoft Office with Win32 COM
One of the most useful things that you can do in an everyday business environment is to integrate
support for Win32 applications. Being able to read data from and write data to such applications can
often be very handy. Your department may not be necessarily be running in a Win32 environment, but
chances are, your management and other project teams are. Mark Hammond's Windows Extensions for
Python allows programmers to interact natively with Win32 applications in their native environment. (It
can be downloaded at the book's Web site.)
The Win32 programming universe is expansive. Most of it available from the Windows Extensions for
Python package, i.e., Windows API, processes, Microsoft Foundation Classes (MFC) Graphical User
Interface (GUI) development, Windows multithreaded programming, services, remote access, pipes,
server-side COM programming, and events. And don't forget about IronPython (http://codeplex.com/
Wiki/View.aspx?ProjectName=IronPython), an implementation of the Python language in C# for the .
NET/Mono development environment. In this section, we are going to focus on one part of the Win32
programming universe, which easily has practical applications for client-side, COM programming.
23.2.1. Client-Side COM Programming
We can use Component Object Model, better known as COM (or its marketing name, ActiveX), to
communicate with tools such as Outlook and Excel. For programmers, the pleasure comes with being
able to "control" a native Office application directly from their Python code.
Specifically, when discussing the use of a COM object, e.g., launching of an application and allowing
code to access methods and data of that applications, this is referred to as COM client-side
programming. Server-side COM programming is where you are implementing a COM object for clients to
access.
Core Note: Python and Microsoft COM (Client-Side) Programming
Python on the Windows 32-bit platform contains connectivity to COM,
a Microsoft interfacing technology that allows objects to talk to one
another, or more higher-level applications to talk to one another,
without any language- or format-dependence. We will see in this
section how the combination of Python and COM (client programming)
presents a unique opportunity to create scripts that can communicate
directly with Microsoft Office applications such as Word, Excel,
PowerPoint, and Outlook.
The prerequisites to this section include running on a Win32 platform with both Python and the Windows
Extensions for Python installed. You must also have one or more Microsoft applications available to try
the examples with. The download instructions for the Windows Extensions should be adequate to get
your system ready to go. Since PythonWin comes with the Extensions distribution, we recommend IDE
for building and testing your Win32 scripts.
In this section, we will show you how you can interact with an Office application. We will present a few
examples, some of them quite useful, and describe how they work in detail. You will also find several of
these at the "Python Cookbook" Web site. We confess to readers that we are not COM or VisualBasic
experts and we are well aware that our examples can be vastly improved. We would like to solicit the
readership to drop us a line and send us any comments, suggestions, or improvements that you would