What is a .pyd file

[Dave Brueck]

> I understand .py, .pyw, .pyc and .dll files.  However, I see .pyd files in
> the ActiveState Python 2.0.203 tree, e.g., multiarray.pyd in the Numeric
> directory; also much of the win32 extensions.  multiarray.pyd looks like a
> Windows DLL and dumpbin seems to agree.  Is it built as a DLL and then
> renamed?  If so, why?

Hi David,

You and dumpbin are right, it is a Windows DLL. The extension is just a
convenient way of marking the file as a Python extension module. This is
particularly useful if your extension module wraps an already-existing
third-party C library. For example, if you saw in your directory:

opengl.dll
opengl.pyd

then it'd be a reasonable bet that the first is the C library and the second
is a Python extension module that uses it.

-Dave