tnetstring 0.2.0

This is a data serialization library. It’s a lot like JSON but it uses a new syntax called “typed netstrings” that Zed has proposed for use in the Mongrel2 webserver. It’s designed to be simpler and easier to implement than JSON, with a happy consequence of also being faster in many cases.

An ordinary netstring is a blob of data prefixed with its length and postfixed with a sanity-checking comma. The string “hello world” encodes like this:

11:hello world,

Typed netstrings add other datatypes by replacing the comma with a type tag. Here’s the integer 12345 encoded as a tnetstring:

5:12345#

And here’s the list [12345,True,0] which mixes integers and bools:

19:5:12345#4:true!1:0#]

Simple enough? This module gives you the following functions:

dump:

dump an object as a tnetstring to a file

dumps:

dump an object as a tnetstring to a string

load:

load a tnetstring-encoded object from a file

loads:

load a tnetstring-encoded object from a string

pop:

pop a tnetstring-encoded object from the front of a string

Note that since parsing a tnetstring requires reading all the data into memory at once, there’s no efficiency gain from using the file-based versions of these functions. They’re only here so you can use load() to read precisely one item from a file or socket without consuming any extra data.

By default tnetstrings work only with byte strings, not unicode. If you want unicode strings then pass an optional encoding to the various functions, like so:

>>> print repr(tnetstring.loads("2:\xce\xb1,"))
'\xce\xb1'
>>>
>>> print repr(tnetstring.loads("2:\xce\xb1,","utf8"))
u'\u03b1'