diff --git a/Lib/site.py b/Lib/site.py
index 7bbd962..3d455e7 100644
--- a/Lib/site.py
+++ b/Lib/site.py
@@ -61,7 +61,10 @@
 # Enable per user site-packages directory
 # set it to False to disable the feature or True to force the feature
 ENABLE_USER_SITE = None
+
 # for distutils.commands.install
+# These values are initialized by the getuserbase() and getusersitepackages()
+# functions, through the main() function when Python starts.
 USER_SITE = None
 USER_BASE = None
 
@@ -205,49 +208,75 @@
 
     return True
 
+def getuserbase():
+    """Returns the `user base` directory path.
+
+    The `user base` directory can be used to store data. If the global
+    variable ``USER_BASE`` is not initialized yet, this function will also set
+    it.
+    """
+    global USER_BASE
+    if USER_BASE is not None:
+        return USER_BASE
+
+    env_base = os.environ.get("PYTHONUSERBASE", None)
+
+    def joinuser(*args):
+        return os.path.expanduser(os.path.join(*args))
+
+    # what about 'os2emx', 'riscos' ?
+    if os.name == "nt":
+        base = os.environ.get("APPDATA") or "~"
+        USER_BASE = env_base if env_base else joinuser(base, "Python")
+    else:
+        USER_BASE = env_base if env_base else joinuser("~", ".local")
+
+    return USER_BASE
+
+def getusersitepackages():
+    """Returns the user-specific site-packages directory path.
+
+    If the global variable ``USER_SITE`` is not initialized yet, this
+    function will also set it.
+    """
+    global USER_SITE
+    user_base = getuserbase() # this will also set USER_BASE
+
+    if USER_SITE is not None:
+        return USER_SITE
+
+    if os.name == "nt":
+        USER_SITE = os.path.join(user_base, "Python" + sys.version[0] +
+                                 sys.version[2], "site-packages")
+    else:
+        USER_SITE = os.path.join(user_base, "lib", "python" + sys.version[:3],
+                                 "site-packages")
+
+    return USER_SITE
 
 def addusersitepackages(known_paths):
     """Add a per user site-package to sys.path
 
     Each user has its own python directory with site-packages in the
     home directory.
-
-    USER_BASE is the root directory for all Python versions
-
-    USER_SITE is the user specific site-packages directory
-
-    USER_SITE/.. can be used for data.
     """
-    global USER_BASE, USER_SITE, ENABLE_USER_SITE
-    env_base = os.environ.get("PYTHONUSERBASE", None)
+    # get the per user site-package path
+    # this call will also make sure USER_BASE and USER_SITE are set
+    user_site = getusersitepackages()
 
-    def joinuser(*args):
-        return os.path.expanduser(os.path.join(*args))
-
-    #if sys.platform in ('os2emx', 'riscos'):
-    #    # Don't know what to put here
-    #    USER_BASE = ''
-    #    USER_SITE = ''
-    if os.name == "nt":
-        base = os.environ.get("APPDATA") or "~"
-        USER_BASE = env_base if env_base else joinuser(base, "Python")
-        USER_SITE = os.path.join(USER_BASE,
-                                 "Python" + sys.version[0] + sys.version[2],
-                                 "site-packages")
-    else:
-        USER_BASE = env_base if env_base else joinuser("~", ".local")
-        USER_SITE = os.path.join(USER_BASE, "lib",
-                                 "python" + sys.version[:3],
-                                 "site-packages")
-
-    if ENABLE_USER_SITE and os.path.isdir(USER_SITE):
-        addsitedir(USER_SITE, known_paths)
+    if ENABLE_USER_SITE and os.path.isdir(user_site):
+        addsitedir(user_site, known_paths)
     return known_paths
 
+def getsitepackages():
+    """Returns a list containing all global site-packages directories
+    (and possibly site-python).
 
-def addsitepackages(known_paths):
-    """Add site-packages (and possibly site-python) to sys.path"""
-    sitedirs = []
+    For each directory present in the global ``PREFIXES``, this function
+    will find its `site-packages` subdirectory depending on the system
+    environment, and will return a list of full paths.
+    """
+    sitepackages = []
     seen = []
 
     for prefix in PREFIXES:
@@ -256,35 +285,36 @@
         seen.append(prefix)
 
         if sys.platform in ('os2emx', 'riscos'):
-            sitedirs.append(os.path.join(prefix, "Lib", "site-packages"))
+            sitepackages.append(os.path.join(prefix, "Lib", "site-packages"))
         elif os.sep == '/':
-            sitedirs.append(os.path.join(prefix, "lib",
+            sitepackages.append(os.path.join(prefix, "lib",
                                         "python" + sys.version[:3],
                                         "site-packages"))
-            sitedirs.append(os.path.join(prefix, "lib", "site-python"))
+            sitepackages.append(os.path.join(prefix, "lib", "site-python"))
         else:
-            sitedirs.append(prefix)
-            sitedirs.append(os.path.join(prefix, "lib", "site-packages"))
-
+            sitepackages.append(prefix)
+            sitepackages.append(os.path.join(prefix, "lib", "site-packages"))
         if sys.platform == "darwin":
             # for framework builds *only* we add the standard Apple
             # locations.
             if 'Python.framework' in prefix:
-                sitedirs.append(
+                sitepackages.append(
                     os.path.expanduser(
                         os.path.join("~", "Library", "Python",
                                      sys.version[:3], "site-packages")))
-                sitedirs.append(
+                sitepackages.append(
                         os.path.join("/Library", "Python",
                             sys.version[:3], "site-packages"))
+    return sitepackages
 
-    for sitedir in sitedirs:
+def addsitepackages(known_paths):
+    """Add site-packages (and possibly site-python) to sys.path"""
+    for sitedir in getsitepackages():
         if os.path.isdir(sitedir):
             addsitedir(sitedir, known_paths)
 
     return known_paths
 
-
 def setBEGINLIBPATH():
     """The OS/2 EMX port has optional extension modules that do double duty
     as DLLs (and must use the .DLL file extension) for other extensions.