clean up, make it work with python3

1 files changed, 30 insertions, 21 deletions

diff --git a/systemd.py b/systemd.py
index 7024103..219bb16 100755
--- a/systemd.py
+++ b/systemd.py
@@ -1,13 +1,29 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python
 #
-# This should be both valid Python 2 and 3, but currently the collectd
-# Python plugin is only Python 2.
+# This should be both valid Python 2 and 3, as the collectd Python
+# plugin can be either Python 2 or 3 (decided at compile time).
+#
+# Oddly, the Arch 'collectd' package chose Python 2, despite using
+# Python 3 as the default system Python.  I assume they have a good
+# reason for it, though I can't find it discussed anywhere.
 
+import sys
 import dbus
 
+# For compatibility with Python 2 & 3
+if sys.version_info.major is 2:
+    def iteritems(d):
+        return d.iteritems()
+else:
+    def iteritems(d):
+        return d.items()
+
+# DBus utility function
 def get_property(dbus_iface, propname):
     return dbus_iface.proxy_object.Get(dbus_iface.dbus_interface, propname, dbus_interface='org.freedesktop.DBus.Properties')
 
+# The main program
+
 def init():
     global system_manager
     system_manager = dbus.Interface(dbus.SystemBus().get_object("org.freedesktop.systemd1", "/org/freedesktop/systemd1"), "org.freedesktop.systemd1.Manager")
@@ -34,31 +50,24 @@ def read():
 
     return dat
 
-def dump(dat):
-    collectd.info("---- dump() ----")
-    for key, val in read().iteritems():
-        if __name__ == '__main__':
-            print("%s => %s" % (key, val))
-        else:
-            collectd.info("%s => %s" % (key, val))
-            collectd.Values(
-                plugin='systemd',
-                type='count',
-                type_instance=key
-            ).dispatch(
-                values=[val]
-            )
-
-
 if __name__ == '__main__':
     init()
-    dump(read())
+    for (key, val) in iteritems(read()):
+        print("%s => %s" % (key, val))
 else:
     import collectd
     def _config(conf):
         pass
     def _read():
-        dump(read())
+        for (key, val) in iteritems(read()):
+            collectd.info("---- dump() ----")
+            collectd.Values(
+                plugin='systemd',
+                type='count',
+                type_instance=key
+            ).dispatch(
+                values=[val]
+            )
     collectd.register_config(_config)
     collectd.register_init(init)
     collectd.register_read(_read)