Build Python interface at install time?

Compiling or Editing the Panda Source
1

It just occurred to me that the current Python interface is locked to Python22.dll :astonished:

Looking at other products, such as numpy or wxWidgets, what tends to happen is either:

  • the installation will automatically build the Python interface files for you, binding them to your own Python installation (eg NumPy)
  • itā€™s possible to download the application for multiple Python versions (wxWidgets)

Would it be possible to do something similar with Panda please?

I think the easiest would probably be:

  • split the Python interface to a separate dll, that links with libpanda.dll and so on. This makes the building and linking process much simpler, because the amount of code involved is considerably smaller
  • pre-run the interrogate to generate the source code files (This bit takes an awfully long time, so this would save a lot of pain)
  • then the installer will simply locate your Python installation, build the provided source code files, and bind them to oneā€™s site-packages

How does that sound?

Hugh

2

By the way, I found the doc for creating the installer that takes the modules, locates the Python installation, and copies the packages into site-packages, amongst other things:

python.org/doc/2.4.1/dist/simple-example.html

Hugh

3

My panda3d install is using python24.dll, but I built it from source that way with makepanda.py.

Or am I missing something?

4

I just canā€™t face compiling from source. :open_mouth:

5

Yeah, me neither.

Two reasons:

  • first is, it takes too long on my machine (and the machine is inoperable during that period)
  • second is, I cant expect other developers on my project to have to go through the same thing

Hugh

6

I would expect if you have multiple developers working on the same project, that you would really want to use a consistent version of python across the board.

If you have some developers working strictly in python, and another team concentrating on extending the c++ sideā€¦makepanda.py will let you build an installable panda distribution like the ones you can download from here. So on my laptop, which I have setup for compiling Panda, I had it build the installer.

On my desktop, which I have just been using for messing with python in panda, I just installed it from my own installer. So my desktop is using the version of ppython that goes with the install of panda that I built from source.

7

I do think it would be a swell idea to either recompile the Python interface layer on-the-fly (especially tricky to do on Windows, where a compiler is not likely to be installed) or provide prebuilt versions for common versions of Python (further exploding our list of downloadables).

Both approaches do have their problems, though. But consider the suggestion on our to-do list.

David

8

Cool - Iā€™d also like to hear some thoughts on moving to an installation similar to say Twisted Matrix that installs under site-packages/twisted.

9

drwr:

Just so you know, Python on Windows can automatically build included C files. It needs the Microsoft .Net 2003 compiler, which coincidentally is the free-to-download one. OTOH, itā€™s looking for registry keys that correspond to the full-blown Microsoft Visual Studio IDE).

So, it would be possible to get Python to recognize the free Toolkit by a suitable .reg file to tweak a registry key.

The Python module that manages this is %PYTHON%\Lib\distutils\msvccompiler.py.

Itā€™s looking for paths under the following:
HKEY_whatever\Software\Microsoft\VisualStudio\7.1\VC\VC_OBJECTS_PLATFORM_INFO\Win32\Directories

Stampson,

Dont supposeā€¦ could you make your prebuilt Python 2.4 binaries publically available please?

Hugh

10

Here is the installer it built for me. This is from makepanda.py with python 2.4.1, and is built without dx7 or dx8, and without helix. The source is unmodified from the distributed source. My only changes were to makepanda.py to get it to compile using the free MS compiler.

If it is a problem for me to provide this link, let me know and of course Iā€™ll take it down.

http://www.westga.edu/~phall/panda/panda3d-1.0.3-python-2.4.1.exe

To clarify thingsā€¦this is a binary created by a member of the community here (myself), and not official. It works for me, your mileage may vary.

11

Not a problem to distribute such things.

However, you might want to test it thoroughly. We havenā€™t done any testing with 2.3 or 2.4, so we donā€™t know if there are any subtle problems. Thatā€™s the only reason I havenā€™t upgraded the main distribution. I donā€™t want to release a version of panda using a particular python distribution until Iā€™m sure itā€™s reliable.

Actually, Iā€™m interested in stackless python, too, if anybody wants to dink around with that.

12

My testing of the above binary with python 2.4.1 has consisted of running the sample programs and poking around with the tutorials. Itā€™s been working for me, which is about all I can say =)

13

Weā€™ve started to migrate to Python 2.4 in the VR Studio. We found a few subtle issues with signedness; Python 2.4 has an automatic upconversion to the ā€œlongā€ type, which gives a limitless range on integers. This means that tricks like (foo | 0x80000000) do not produce a negative number. Python 2.2 didnā€™t do this.

The practical difference is only an issue in some very subtle cases, especially having to do with networking. I suspect you can run Panda in Python 2.4 for quite a while before you notice any of the problems that we came across.

When we eventually get Panda3D version 1.1 ready, of course, it will include all of the fixes we made for Python 2.4.

David

14

Awesome Stampson!

Hugh