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.
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: booleans, integers, floating-point
numbers, complex numbers, strings, bytes, bytearrays, tuples, lists, sets,
frozensets, dictionaries, and code objects (if allow_code is true),
where it should be understood that
tuples, lists, sets, frozensets and dictionaries are only supported as long as
the values contained therein are themselves supported. The
singletons None
, Ellipsis
and StopIteration
can also be
marshalled and unmarshalled.
For format version lower than 3, recursive lists, sets and dictionaries cannot
be written (see below).
Il existe des fonctions de lecture-écriture de fichiers ainsi que des fonctions opérant sur des objets octet.
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 byload()
. 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 argumentsvalue
,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
orTypeError
. 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 » parNone
.Modifié dans la version 3.10: This call used to raise a
code.__new__
audit event for each code object. Now it raises a singlemarshal.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 aValueError
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 argumentsvalue
,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
orTypeError
. Code objects are only supported if allow_code is true. Extra bytes in the input are ignored.Raises an auditing event
marshal.loads
with argumentbytes
.Modifié dans la version 3.10: This call used to raise a
code.__new__
audit event for each code object. Now it raises a singlemarshal.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 format, version 1 shares interned strings and version 2 uses a binary format for floating-point numbers. Version 3 adds support for object instancing and recursion. The current version is 4.
Notes