twisted.spread.jelly

S-expression-based persistence of python objects.

It does something very much like Pickle; however, pickle's main goal seems to be efficiency (both in space and time); jelly's main goals are security, human readability, and portability to other environments.

This is how Jelly converts various objects to s-expressions.

Boolean:

    True --> ['boolean', 'true']

Integer:

    1 --> 1

List:

    [1, 2] --> ['list', 1, 2]

String:

    "hello" --> "hello"

Float:

    2.3 --> 2.3

Dictionary:

    {'a': 1, 'b': 'c'} --> ['dictionary', ['b', 'c'], ['a', 1]]

Module:

    UserString --> ['module', 'UserString']

Class:

    UserString.UserString --> ['class', ['module', 'UserString'], 'UserString']

Function:

    string.join --> ['function', 'join', ['module', 'string']]

Instance: s is an instance of UserString.UserString, with a __dict__ {'data': 'hello'}:

    ["UserString.UserString", ['dictionary', ['data', 'hello']]]

Class Method: UserString.UserString.center:

    ['method', 'center', ['None'], ['class', ['module', 'UserString'],
     'UserString']]

Instance Method: s.center, where s is an instance of UserString.UserString:

    ['method', 'center', ['instance', ['reference', 1, ['class',
    ['module', 'UserString'], 'UserString']], ['dictionary', ['data', 'd']]],
    ['dereference', 1]]

The set builtin and the sets.Set class are serialized to the same thing, and unserialized to set if available, else to sets.Set. It means that there's a possibility of type switching in the serialization process. The solution is to always use set.

The same rule applies for frozenset and sets.ImmutableSet.