Although many said that it cannot be installed by pip, however, I am using virtualenv, it's worth to give it a try.
$ pip install dbus-python
The first error is:
checking for DBUS_GLIB... no
configure: error: Package requirements (dbus-glib-1 >= 0.70) were not met:
No package 'dbus-glib-1' found
Apparently dbus-gdb-1-dev is missing, so I installed "libdbus-glib-1-dev"
Successfully installed dbus-python
dbus-python-1.2.4 is installed by pip !!!