"marshal" --- Internal Python object serialization
**************************************************

======================================================================

This module contains functions that can read and write Python values
in a binary format.  The format is specific to Python, but independent
of machine architecture issues (e.g., you can write a Python value to
a file on a PC, transport the file to a Mac, and read it back there).
Details of the format are undocumented on purpose; it may change
between Python versions (although it rarely does). [1]

This is not a general "persistence" module.  For general persistence
and transfer of Python objects through RPC calls, see the modules
"pickle" and "shelve".  The "marshal" module exists mainly to support
reading and writing the "pseudo-compiled" code for Python modules of
".pyc" files. Therefore, the Python maintainers reserve the right to
modify the marshal format in backward incompatible ways should the
need arise. The format of code objects is not compatible between
Python versions, even if the version of the format is the same. De-
serializing a code object in the incorrect Python version has
undefined behavior. If you're serializing and de-serializing Python
objects, use the "pickle" module instead -- the performance is
comparable, version independence is guaranteed, and pickle supports a
substantially wider range of objects than marshal.

Avertissement:

  N'utilisez pas le module "marshal" pour lire des données erronées ou
  malveillantes.  Ne démantelez jamais des données reçues d'une source
  non fiable ou non authentifiée.

Il existe des fonctions de lecture-écriture de fichiers ainsi que des
fonctions opérant sur des objets octet.

Not all Python object types are supported; in general, only objects
whose value is independent from a particular invocation of Python can
be written and read by this module.  The following types are
supported:

* Numeric types: "int", "bool", "float", "complex".

* Strings ("str") and "bytes". *Bytes-like objects* like "bytearray"
  are marshalled as "bytes".

* Containers: "tuple", "list", "set", "frozenset", and (since
  "version" 5), "slice". It should be understood that these are
  supported only if the values contained therein are themselves
  supported. Recursive containers are supported since "version" 3.

* The singletons "None", "Ellipsis" and "StopIteration".

* "code" objects, if *allow_code* is true. See note above about
  version dependence.

Modifié dans la version 3.4:

* Added format version 3, which supports marshalling recursive lists,
  sets and dictionaries.

* Added format version 4, which supports efficient representations of
  short strings.

Modifié dans la version 3.14: Added format version 5, which allows
marshalling slices.

Le module définit ces fonctions :

marshal.dump(value, file, version=version, /, *, allow_code=True)

   Écrit la valeur sur le fichier ouvert.  La valeur doit être un type
   pris en charge.  Le fichier doit être un *fichier binaire* ouvert
   en écriture.

   If the value has (or contains an object that has) an unsupported
   type, a "ValueError" exception is raised --- but garbage data will
   also be written to the file.  The object will not be properly read
   back by "load()". Code objects are only supported if *allow_code*
   is true.

   L'argument *version* indique le format de données que le "dump"
   doit utiliser (voir ci-dessous).

   Raises an auditing event "marshal.dumps" with arguments "value",
   "version".

   Modifié dans la version 3.13: Added the *allow_code* parameter.

marshal.load(file, /, *, allow_code=True)

   Read one value from the open file and return it.  If no valid value
   is read (e.g. because the data has a different Python version's
   incompatible marshal format), raise "EOFError", "ValueError" or
   "TypeError". Code objects are only supported if *allow_code* is
   true. The file must be a readable *binary file*.

   Raises an auditing event "marshal.load" with no arguments.

   Note:

     Si un objet contenant un type non pris en charge a été dé-compilé
     avec "dump()", "load()" remplacera le type non « dé-compilable »
     par "None".

   Modifié dans la version 3.10: This call used to raise a
   "code.__new__" audit event for each code object. Now it raises a
   single "marshal.load" event for the entire load operation.

   Modifié dans la version 3.13: Added the *allow_code* parameter.

marshal.dumps(value, version=version, /, *, allow_code=True)

   Return the bytes object that would be written to a file by
   "dump(value, file)".  The value must be a supported type.  Raise a
   "ValueError" exception if value has (or contains an object that
   has) an unsupported type. Code objects are only supported if
   *allow_code* is true.

   L'argument *version* indique le format de données que "dumps"
   doivent utiliser (voir ci-dessous).

   Raises an auditing event "marshal.dumps" with arguments "value",
   "version".

   Modifié dans la version 3.13: Added the *allow_code* parameter.

marshal.loads(bytes, /, *, allow_code=True)

   Convert the *bytes-like object* to a value.  If no valid value is
   found, raise "EOFError", "ValueError" or "TypeError". Code objects
   are only supported if *allow_code* is true. Extra bytes in the
   input are ignored.

   Raises an auditing event "marshal.loads" with argument "bytes".

   Modifié dans la version 3.10: This call used to raise a
   "code.__new__" audit event for each code object. Now it raises a
   single "marshal.loads" event for the entire load operation.

   Modifié dans la version 3.13: Added the *allow_code* parameter.

De plus, les constantes suivantes sont définies :

marshal.version

   Indicates the format that the module uses. Version 0 is the
   historical first version; subsequent versions add new features.
   Generally, a new version becomes the default when it is introduced.

   +---------+-----------------+------------------------------------------------------+
   | Version | Available since | New features                                         |
   |=========|=================|======================================================|
   | 1       | Python 2.4      | Sharing interned strings                             |
   +---------+-----------------+------------------------------------------------------+
   | 2       | Python 2.5      | Binary representation of floats                      |
   +---------+-----------------+------------------------------------------------------+
   | 3       | Python 3.4      | Support for object instancing and recursion          |
   +---------+-----------------+------------------------------------------------------+
   | 4       | Python 3.4      | Efficient representation of short strings            |
   +---------+-----------------+------------------------------------------------------+
   | 5       | Python 3.14     | Support for "slice" objects                          |
   +---------+-----------------+------------------------------------------------------+

-[ Notes ]-

[1] Le nom de ce module provient d'un peu de terminologie utilisée par
    les concepteurs de Modula-3 (entre autres), qui utilisent le terme
    *marshalling* pour l'envoi de données sous une forme autonome. À
    proprement parler, *to marshal* signifie convertir certaines
    données d'une forme interne à une forme externe (dans une mémoire
    tampon RPC par exemple) et *unmarshalling* désigne le processus
    inverse.
