Improve determining an appropriate python install prefix.

trunk/python-prefix.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+
+import sys
+import os.path
+import site
+
+def main():
+    if len(sys.argv) != 2:
+        msg = 'usage: %s <prefix>\n' % os.path.basename(sys.argv[0])
+        sys.stderr.write(msg)
+        return 1
+    python_prefix = sys.argv[1]
+    prefix = None
+    for p in sys.path:
+        if python_prefix in p:
+            prefix = python_prefix
+            break
+    if not prefix:
+        prefix = site.PREFIXES[-1]
+    print prefix
+    return 0
+
+if __name__ == '__main__':
+    sys.exit(main())