[sugar] Data Transport between nodes

Simon McVittie simon.mcvittie
Wed Oct 3 06:24:40 EDT 2007

On Tue, 02 Oct 2007 at 17:43:41 -0400, Benjamin M. Schwartz wrote:
>  I used these to send arbitrary bytes over the Tube, which only supports utf8.

This isn't actually true. If a D-Bus method is declared with signature 's'
(string) it only supports unicode or UTF-8 str objects. If no signature is
declared but you use a str argument, dbus-python will guess that you
wanted signature 's' and the string has to be UTF-8.

However, if your method is declared with signature 'ay' (byte array) you
can pass arbitrary binary data. You probably want to put
byte_arrays=True in the @method decorator, so the method will get its
input as a dbus.ByteArray (a subclass of str) rather than as a
dbus.Array of dbus.Bytes (subclasses of: a list of ints).

If your data has some other internal structure, other D-Bus types may be
more appropriate (e.g. you might want a list of floats, which in D-Bus
terminology would be an array of double, signature 'ad').

Similar notes apply to signals. See
http://dbus.freedesktop.org/doc/dbus-python/doc/tutorial.html for more

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