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1:mod:`pickletools` --- Tools for pickle developers
2==================================================
3
4.. module:: pickletools
5   :synopsis: Contains extensive comments about the pickle protocols and pickle-machine
6              opcodes, as well as some useful functions.
7
8
9.. versionadded:: 2.3
10
11**Source code:** :source:`Lib/pickletools.py`
12
13--------------
14
15This module contains various constants relating to the intimate details of the
16:mod:`pickle` module, some lengthy comments about the implementation, and a few
17useful functions for analyzing pickled data.  The contents of this module are
18useful for Python core developers who are working on the :mod:`pickle` and
19:mod:`cPickle` implementations; ordinary users of the :mod:`pickle` module
20probably won't find the :mod:`pickletools` module relevant.
21
22
23.. function:: dis(pickle, out=None, memo=None, indentlevel=4)
24
25   Outputs a symbolic disassembly of the pickle to the file-like object *out*,
26   defaulting to ``sys.stdout``.  *pickle* can be a string or a file-like object.
27   *memo* can be a Python dictionary that will be used as the pickle's memo; it can
28   be used to perform disassemblies across multiple pickles created by the same
29   pickler. Successive levels, indicated by ``MARK`` opcodes in the stream, are
30   indented by *indentlevel* spaces.
31
32
33.. function:: genops(pickle)
34
35   Provides an :term:`iterator` over all of the opcodes in a pickle, returning a
36   sequence of ``(opcode, arg, pos)`` triples.  *opcode* is an instance of an
37   :class:`OpcodeInfo` class; *arg* is the decoded value, as a Python object, of
38   the opcode's argument; *pos* is the position at which this opcode is located.
39   *pickle* can be a string or a file-like object.
40
41.. function:: optimize(picklestring)
42
43   Returns a new equivalent pickle string after eliminating unused ``PUT``
44   opcodes. The optimized pickle is shorter, takes less transmission time,
45   requires less storage space, and unpickles more efficiently.
46
47   .. versionadded:: 2.6
48