better checking for whether our target python is python 3

SConstruct

@@ -199,6 +199,7 @@ def pretty_dep(dep):
     return dep
 
 # local file to hold custom user configuration variables
+# Todo check timestamp, reload if changed?
 SCONS_LOCAL_CONFIG = 'config.py'
 # build log
 SCONS_LOCAL_LOG = 'config.log'
@@ -1093,12 +1094,7 @@ if not preconfigured:
                 color_print(1,"Cannot run python interpreter at '%s', make sure that you have the permissions to execute it." % env['PYTHON'])
                 Exit(1)
             
-            res = os.popen('''%s -c "print 1"''' % env['PYTHON'])
-            if res.read() == '1':
-                py3 = False
-            else:
-                py3 = True
-            #sys.version_info.major == 3
+            py3 = 'True' in os.popen('''%s -c "import sys as s;s.stdout.write(str(s.version_info[0] == 3))"''' % env['PYTHON']).read().strip()
 
             if py3:
                 sys_prefix = '''%s -c "import sys; print(sys.prefix)"''' % env['PYTHON']

bindings/python/SConscript

@@ -19,9 +19,7 @@
 #
 # $Id$
 
-import glob
-import re
-import os
+import os, re, sys, glob
 from subprocess import Popen, PIPE
 
 
@@ -37,6 +35,10 @@ def call(cmd, silent=True):
 def run_2to3(*args,**kwargs):
     call('2to3 -w %s' % os.path.dirname(kwargs['target'][0].path))
 
+def is_py3():
+    return 'True' in os.popen('''%s -c "import sys as s;s.stdout.write(str(s.version_info[0] == 3))"''' % env['PYTHON']).read().strip()
+
+
 prefix = env['PREFIX']
 target_path = env['PYTHON_INSTALL_LOCATION'] + '/mapnik2'
 
@@ -51,6 +53,9 @@ if env['BOOST_PYTHON_LIB']:
     else:
         libraries.append(env['BOOST_PYTHON_LIB'].replace('lib','',1))
 else:
+    if is_py3():
+        libraries.append('boost_python3%s' % env['BOOST_APPEND'])
+    else:
         libraries.append('boost_python%s' % env['BOOST_APPEND'])
 
 if env['PLATFORM'] == 'Darwin':
@@ -199,6 +204,7 @@ if 'uninstall' not in COMMAND_LINE_TARGETS:
     pymapniklib = env.Install(target_path,_mapnik)
     py_env.Alias(target='install',source=pymapniklib)
     if pymapniklib and 'install' in COMMAND_LINE_TARGETS:
+        if is_py3():
             env.AddPostAction(pymapniklib, run_2to3)