[Distutils] install location(s)

[Andrew Dalke]

This is an easy couple of questions (I hope).

1)
What is the correct location for "pure" python module installations?

 $(prefix)/lib/python$VERSION/site-packages
or
 $(prefix)/lib/site-python

I believe most packages tend to install in site-packages but
site-python makes more sense since I usually write my modules
to deal with differences in python versions.

2) where should python shared libraries be placed if you want
to have one install of python per site which includes different
architectures?  (For example, we may distribute our software on
both SGI and Linux boxes.)

As I understand it now, the python specific .so files need to be
on the PYTHONPATH, which currently contains no information about
the specific platform.  The only information available is from
sys.platform (along with os.uname) and that doesn't appear
sufficient to distinguish between different SGI binary interfaces.

Specifically, SGIs have 3 interfaces: "old" 32, "new" 32 and 64.
These are specified during compilation by the environment variable
SGI_ABI or by the command-line options (-32/-o32, -n32, -64). In
theory we could compile libraries for each of the different
interfaces, though we only support o32 at present.  To do it fully
we would have to write a wrapper script which runs the specified
ABI version of Python ... oh, but then we could modify the
PYTHONPATH to reflect the differences.

Has there been a proposal for how to distribute/manage/install
distributions with multiple architectures?  The best I can think
of for now is to modify site.py to add 
                        os.path.join(prefix,
                                     "lib",
                                     "python" + sys.version[:3],
                                     "site-packages",
                                     sys.platform),

to the sitedirs list.  Does this make sense, and should it be
added to the 1.5.2 (or discussed more on c.l.py)?

						Andrew
						dalke@bioreason.com


BTW, here's how SGI's java, which is only for 32 bits, manages
things.  "java" is actuall a shell script containing the following
three snippets:


# use -n32 binaries by default

if [[ $SGI_ABI = -32 ]]
then
  export JAVA_N32=0
elif [[ $SGI_ABI = -o32 ]]
then
  export JAVA_N32=0
else
  export JAVA_N32=1
fi


    case $a in
        -32)
            JAVA_N32=0
            shift
            ;;
        -o32)
            JAVA_N32=0
            shift
            ;;
        -n32)
            JAVA_N32=1
            shift
            ;;


if [ $JAVA_N32 = 1 ]
then
  check_path $LD_LIBRARYN32_PATH "LD_LIBRARYN32_PATH"
  if [ -z "$LD_LIBRARYN32_PATH" ]
  then
    if [ -z "$LD_LIBRARY_PATH" ]
    then
      LD_LIBRARYN32_PATH=$JAVA_HOME/lib32/sgi/$THREADS_TYPE
    else
      check_path $LD_LIBRARY_PATH "LD_LIBRARY_PATH"
      LD_LIBRARYN32_PATH="$JAVA_HOME/lib32/sgi/$THREADS_TYPE:$LD_LIBRARY_PATH"
    fi
  else
    LD_LIBRARYN32_PATH="$JAVA_HOME/lib32/sgi/$THREADS_TYPE:$LD_LIBRARYN32_PATH"
  fi
  export LD_LIBRARYN32_PATH
  prog=$JAVA_HOME/bin32/sgi/${THREADS_TYPE}/${progname}
else
  check_path $LD_LIBRARY_PATH "LD_LIBRARY_PATH"
  if [ -z "$LD_LIBRARY_PATH" ]
  then
    LD_LIBRARY_PATH=$JAVA_HOME/lib/sgi/$THREADS_TYPE
  else
    LD_LIBRARY_PATH="$JAVA_HOME/lib/sgi/$THREADS_TYPE:$LD_LIBRARY_PATH"
  fi
  export LD_LIBRARY_PATH
  prog=$JAVA_HOME/bin/sgi/${THREADS_TYPE}/${progname}
fi