cpython/PC/example_nt

Example Python extension for Windows NT

=======================================



This directory contains everything needed (except for the Python

distribution!) to build a Python extension module using Microsoft VC++

("Developer Studio") version 6.  It has been tested with VC++ 6.0 on Python

2.1a1.  You can also use earlier versions of VC to build Python extensions,

but the sample VC project file (example.dsw in this directory) is in VC 6

format.



COPY THIS DIRECTORY!

--------------------

This "example_nt" directory is a subdirectory of the PC directory, in order

to keep all the PC-specific files under the same directory.  However, the

example_nt directory can't actually be used from this location.  You first

need to copy or move it up one level, so that example_nt is a direct

sibling of the PC\ and Include\ directories.  Do all your work from within

this new location -- sorry, but you'll be sorry if you don't.



OPEN THE PROJECT

----------------

From VC 6.x, use the

    File -> Open Workspace...

dialog (*not* the "File -> Open..." dialog!).  Navigate to and select the

file "example.dsw", in the *copy* of the example_nt directory you made

above.

Click Open.



BUILD THE EXAMPLE DLL

---------------------

In order to check that everything is set up right, try building:



1. Select a configuration.  This step is optional.  Do

       Build -> Select Active Configuration...

   and select either "example - Win32 Release" or "example - Win32 Debug".

   If you skip this step, you'll use the Debug configuration by default.



2. Build the DLL.  Do

       Build -> Build example_d.dll

   in Debug mode, or

       Build -> Build example.dll

   in Release mode.

   This creates all intermediate and result files in a subdirectory which

   is called either Debug or Release, depending on which configuration you

   picked in the preceding step.



TESTING THE DEBUG-MODE DLL

--------------------------

Once the Debug build has succeeded, bring up a DOS box, and cd to

example_nt\Debug.  You should now be able to repeat the following session

("C>" is the DOS prompt, ">>>" is the Python prompt) (note that various

debug output from Python may not match this screen dump exactly):



    C>..\..\PCbuild\python_d

    Adding parser accelerators ...

    Done.

    Python 2.1a1 (#9, Jan 17 2001, 23:26:37) [MSC 32 bit (Intel)] on win32

    Type "copyright", "credits" or "license" for more information.

    >>> import example

    [4897 refs]

    >>> example.foo()

    Hello, world

    [4903 refs]

    >>>



TESTING THE RELEASE-MODE DLL

----------------------------

Once the Release build has succeeded, bring up a DOS box, and cd to

example_nt\Release.  You should now be able to repeat the following session

("C>" is the DOS prompt, ">>>" is the Python prompt):



    C>..\..\PCbuild\python

    Python 2.1a1 (#9, Jan 17 2001, 23:26:37) [MSC 32 bit (Intel)] on win32

    Type "copyright", "credits" or "license" for more information.

    >>> import example

    >>> example.foo()

    Hello, world

    >>>



Congratulations!  You've successfully built your first Python extension

module.



CREATING YOUR OWN PROJECT

-------------------------

Choose a name ("spam" is always a winner :-) and create a directory for

it.  Copy your C sources into it.  Note that the module source file name

does not necessarily have to match the module name, but the "init" function

name should match the module name -- i.e. you can only import a module

"spam" if its init function is called "initspam()", and it should call

Py_InitModule with the string "spam" as its first argument (use the minimal

example.c in this directory as a guide).  By convention, it lives in a file

called "spam.c" or "spammodule.c".  The output file should be called

"spam.dll" or "spam.pyd" (the latter is supported to avoid confusion with a

system library "spam.dll" to which your module could be a Python interface)

in Release mode, or spam_d.dll or spam_d.pyd in Debug mode.



Now your options are:



1) Copy example.dsw and example.dsp, rename them to spam.*, and edit them

by hand.



or



2) Create a brand new project; instructions are below.



In either case, copy example_nt\example.def to spam\spam.def, and edit the

new spam.def so its second line contains the string "initspam".  If you

created a new project yourself, add the file spam.def to the project now.

(This is an annoying little file with only two lines.  An alternative

approach is to forget about the .def file, and add the option

"/export:initspam" somewhere to the Link settings, by manually editing the

"Project Options" box).



You are now all set to build your extension, unless it requires other

external libraries, include files, etc.  See Python's Extending and

Embedding manual for instructions on how to write an extension.





CREATING A BRAND NEW PROJECT

----------------------------

Use the

    File -> New... -> Projects

dialog to create a new Project Workspace.  Select "Win32 Dynamic-Link

Library", enter the name ("spam"), and make sure the "Location" is set to

the spam directory you have created (which should be a direct subdirectory

of the Python build tree, a sibling of Include and PC).  Select Win32 as the

platform (in my version, this is the only choice).  Make sure the "Create

new workspace" radio button is selected.  Click OK.



Now open the

    Project -> Settings...

dialog.  (Impressive, isn't it? :-) You only need to change a few

settings.  Make sure "All Configurations" is selected from the "Settings

for:" dropdown list.  Select the "C/C++" tab.  Choose the "Preprocessor"

category in the popup menu at the top.  Type the following text in the

entry box labeled "Addditional include directories:"



    ..\Include,..\PC



Then, choose the "Input" category in the Link tab, and enter

    ..\PCbuild

in the "Additional library path:" box.



Now you need to add some mode-specific settings:



Select "Win32 Release" in the "Settings for:" dropdown list.  Click the

"Link" tab, choose the "Input" Category, and append "python21.lib" to the

list in the "Object/library modules:" box.



Select "Win32 Debug" in the "Settings for:" dropdown list, and append

"python21_d.lib" to the list in the "Object/library modules:" box.  Then

click on the C/C++ tab, select "Code Generation" from the "Category:"

dropdown list, and select "Debug Multithreaded DLL" from the "Use run-time

library:" dropdown list.



Select "Win32 Release" again from the "Settings for:" dropdown list.

Select "Multithreaded DLL" from the "Use run-time library:" dropdown list.



That's all <wink>.



You should now create the file spam.def as instructed in the previous

section.  Then chose the

    Insert -> Files into Project...

dialog.  Set the pattern to *.* and select both spam.c and spam.def and

click OK.  (Inserting them one by one is fine too.)