Word Hacks [Electronic resources] نسخه متنی

Hack 88 Use Python from Word

This hack shows you how to create standalone
Python objects that you can run from within Word using
VBA.

[Hack #85]
showed you how to control Word from Python
using COM automation [Hack #84] .
Python also includes a way to create your own COM objects, which you
can then use from within a Word macro.

This hack assumes that you have Python installed on your system and that you can run Python scripts from the DOS command line. To download Python (for free), go to http://www.python.org. For detailed information on using Python on Windows systems, see O'Reilly's Python Programming on Win32.

This sample shows you how to create a COM object with a single
method, SplitString. This method has semantics
identical to the standard Python function
string.split: the first argument is the string to
split, and the second (optional) argument is the delimiter string.

There are two steps to implement COM objects in Python:

Define a Python class with the methods and properties you wish to
expose.

Annotate the Python class with special attributes required by the
PythonCOM framework to expose the Python class as a COM object.

Both of these steps are accomplished by the code in the following
section.

9.10.1 The Code

The following Python code shows a small COM server:

#SimpleCOMServer.py - A sample COM server - almost as small as they come!
#
# We expose a single method in a Python COM object
class PythonUtilities:
_public_methods_ = [ 'SplitString' ]
_reg_progid_ = "PythonDemo.Utilities"
# NEVER copy the following ID!
# Use "print pythoncom.CreateGuid( )" to make a new one
_reg_clsid_  = "{40CEA5F8-4D4C-4655-BD8B-0E7B6A26B556}"
def SplitString(self, val, item=None):
import string
if item != None: item = str(item)
return string.split(str(val), item)
# Add code so that when this script is run by
# Python.exe, it self-registers
if __name__=='__main_  _':
print "Registering COM server..."
import win32com.server.register
win32com.server.register.UseCommandLine(PythonUtilities)

Save this code as SimpleCOMServer.py.

Note the following line from the script:

_reg_clsid_  = "{40CEA5F8-4D4C-4655-BD8B-0E7B6A26B556}"

In this line, you assign a unique identifier to your COM object.
Windows uses these identifiers to keep track of the components
installed on the system. Do not just copy the
one from this sample into your own code. You need to create your own,
which you can do easily with Python right from the DOS command line:

> python
>>> import pythoncom
>>> print pythoncom.CreateGuid( )

This prints a new, unique identifier to the command line. Use the
number created on your system in place of the sample in the code
above.

9.10.2 Running the Hack

Now you'll need to register the object with COM. You
can do this by executing the code as a normal Python script. From the
DOS command line, type:

> python SimpleCOMServer.py

After running the script, you'll see the following
messages:

Registering COM server...
Registered: PythonDemo.Utilities

Now, to test the COM object from
Word, put the following macro in the
template of your choice [Hack #50]
and run it from ToolsMacroMacros:

Sub PythonObj( )
Dim py As Object
Dim vResponse As Variant
Dim v As Variant
Set py = CreateObject("PythonDemo.Utilities")
vResponse = py.SplitString("Hello from Python!")
For Each v In vResponse
MsgBox v
Next v
End Sub

Running this code displays three message boxes, each showing one of
the words in the phrase "Hello from
Python!"

The default delimiter is a space, but you can also provide a
delimiter string:

vResponse = py.SplitString("Hello, Word", ",")

To keep things tidy and help keep your registry clean, run your
script again from the command line to unregister the sample COM
server, but this time use the --unregister
argument:

> python SimpleCOMServer.py --unregister

Mark Hammond