Tickle
Friday, December 28th, 2007Tickle is a small Python serializer like Pickle. It however aims at generating smaller output:
>>> len(tickle('hello'))
7
>>> s = StringIO.StringIO()
>>> pickle.dump('hello', s)
>>> len(s.getvalue())
13
Though the difference is and remains quite small, this alone is useful for serialization of small things in the case of for instance RPC. However, usually you already know what kind of data to expect and you don’t really bother about the type information. This can be done by specifying a template:
>>> obj = []
>>> for i in xrange(100):
obj.append((i, str(i)))
>>> len(tickle(obj))
629
>>> len(tickle(obj, template=(tuple, \
((tuple,((int,), (str,))),)*100)))
390
(Instead the *100 an iterator could be constructed, but that would clutter the example even more than it already is.) In comparison:
>>> s = StringIO.StringIO(); pickle.dump(obj, s)
>>> len(s.getvalue())
1680
One big disadvantage of Tickle is speed. Pickle has got a nice C implementation, which is quite fast. Psyco helps a bit but not really enough for really big things. Even more so pickle is a bit smarter: it builds a LUT for instances to avoid duplicate data. However, in the situations where Tickle will be used (by me at least) that isn’t too big of an issue.