[Python-bugs-list] [Bug #127722] getpythonregpath fails

[noreply@sourceforge.net]

Bug #127722, was updated on 2001-Jan-05 21:16
Here is a current snapshot of the bug.

Project: Python
Category: Windows
Status: Closed
Resolution: Fixed
Bug Group: Platform-specific
Priority: 5
Submitted by: effbiae
Assigned to : mhammond
Summary: getpythonregpath fails

Details: Hi,

I'm on Win95 (regrettably).

I found that while experimenting with embedding Python in C, I initialized
the interpreter, and got the message:
  'import site' failed; use -v for traceback

If I putenv("PYTHONHOME=C:\python20"), this disappears.  Also, if I put the
executable in C:\python20, the problem disappears.  

Please excuse any stupidity that follows as I am a newby to the windows
registy.

in the file:
  Pc\getpathp.c

in the function:
  static char *
  getpythonregpath(HKEY keyBase, int skipcore)

in the call:
  rc = RegQueryInfoKey(newKey, NULL, NULL, NULL, &numKeys, NULL, NULL, 
	                NULL, NULL, &dataSize, NULL, NULL);

numKeys is being set to 0 because in my installation of Python 2.0, the
registry key:
  HKEY_LOCAL_MACHINE\\Software\\Python\\PythonCore\\PythonPath\

has no subkeys. It has the 'default' (?) value:
  
C:\Python20\Lib\plat-win;C:\Python20\Lib;C:\Python20\DLLs;C:\Python20\Lib\lib-tk

(I do not have HKEY_CURRENT_USER\\Software\\Python\\PythonCore\\PythonPath 
-- in fact I do not have HKEY_CURRENT_USER\\Software\\Python)

Anyway, it looks like the code assumes 'numKeys > 0', which is not the case
at my run-time.

It appears that the the registry editing part of the installation program
may have changed recently, and this file has not been updated accordingly. 


Also, the doco for the Python/C API says that the PATH environment variable
may be examined to locate the python executable, but it appears that in the
Win version of Python2.0, PATH is ignored.  Is there a reason why PATH is
not examined in the Win version?



Follow-Ups:

Date: 2001-Feb-23 03:49
By: mhammond

Comment:
Fixed in rev 1.23 of PC/getpath.c.  See patch #103933
-------------------------------------------------------

Date: 2001-Jan-30 21:01
By: mhammond

Comment:
This is "by design" - see my comments at
https://sourceforge.net/bugs/?func=detailbug&group_id=5470&bug_id=129584

Note that there is no default that uses absolute paths (ie, the "C:\..."
you referenced).  This is the Python code determining its own core, and
thereby ignoring the registry key for the core (sub-keys are still used)

I believe the code you reference is fine, and working as designed (but that
may not be how you like <wink>).  My testing shows the code working in an
identical fashion regardless of the number of subkeys.

Also, setting PYTHONHOME is working as designed - this env var tells Python
to not search for its home, and to not use the registry key, but assume the
directory specified is valid, and build its core path from that.

Marking as "works for me" and closing.
-------------------------------------------------------

Date: 2001-Jan-09 17:13
By: mhammond

Comment:
Happy to look at this, but it will probably need to wait until I return to
Oz - early Feb.
-------------------------------------------------------

Date: 2001-Jan-07 21:37
By: tim_one

Comment:
Assigned to MarkH cuz he might actually think he knows what the code is
doing <wink..
-------------------------------------------------------

Date: 2001-Jan-07 15:48
By: fdrake

Comment:
Assigned to Tim since this is on Windows.
-------------------------------------------------------

For detailed info, follow this link:
http://sourceforge.net/bugs/?func=detailbug&bug_id=127722&group_id=5470