Vous êtes un professionnel et vous avez besoin d'une formation ?
Coder avec une
Intelligence Artificielle
Voir le programme détaillé
Module « numpy.matlib »
Classe « dtype »
Informations générales
Héritage
builtins.object
dtype
Définition
class dtype(builtins.object):
help(dtype)
dtype(dtype, align=False, copy=False, [metadata])
Create a data type object.
A numpy array is homogeneous, and contains elements described by a
dtype object. A dtype object can be constructed from different
combinations of fundamental numeric types.
Parameters
----------
dtype
Object to be converted to a data type object.
align : bool, optional
Add padding to the fields to match what a C compiler would output
for a similar C-struct. Can be ``True`` only if `obj` is a dictionary
or a comma-separated string. If a struct dtype is being created,
this also sets a sticky alignment flag ``isalignedstruct``.
copy : bool, optional
Make a new copy of the data-type object. If ``False``, the result
may just be a reference to a built-in data-type object.
metadata : dict, optional
An optional dictionary with dtype metadata.
See also
--------
result_type
Examples
--------
Using array-scalar type:
>>> import numpy as np
>>> np.dtype(np.int16)
dtype('int16')
Structured type, one field name 'f1', containing int16:
>>> np.dtype([('f1', np.int16)])
dtype([('f1', '<i2')])
Structured type, one field named 'f1', in itself containing a structured
type with one field:
>>> np.dtype([('f1', [('f1', np.int16)])])
dtype([('f1', [('f1', '<i2')])])
Structured type, two fields: the first field contains an unsigned int, the
second an int32:
>>> np.dtype([('f1', np.uint64), ('f2', np.int32)])
dtype([('f1', '<u8'), ('f2', '<i4')])
Using array-protocol type strings:
>>> np.dtype([('a','f8'),('b','S10')])
dtype([('a', '<f8'), ('b', 'S10')])
Using comma-separated field formats. The shape is (2,3):
>>> np.dtype("i4, (2,3)f8")
dtype([('f0', '<i4'), ('f1', '<f8', (2, 3))])
Using tuples. ``int`` is a fixed type, 3 the field's shape. ``void``
is a flexible type, here of size 10:
>>> np.dtype([('hello',(np.int64,3)),('world',np.void,10)])
dtype([('hello', '<i8', (3,)), ('world', 'V10')])
Subdivide ``int16`` into 2 ``int8``'s, called x and y. 0 and 1 are
the offsets in bytes:
>>> np.dtype((np.int16, {'x':(np.int8,0), 'y':(np.int8,1)}))
dtype((numpy.int16, [('x', 'i1'), ('y', 'i1')]))
Using dictionaries. Two fields named 'gender' and 'age':
>>> np.dtype({'names':['gender','age'], 'formats':['S1',np.uint8]})
dtype([('gender', 'S1'), ('age', 'u1')])
Offsets in bytes, here 0 and 25:
>>> np.dtype({'surname':('S25',0),'age':(np.uint8,25)})
dtype([('surname', 'S25'), ('age', 'u1')])
Constructeur(s)
Liste des attributs statiques
alignment | <member 'alignment' of 'numpy.dtype' objects> |
base | <attribute 'base' of 'numpy.dtype' objects> |
byteorder | <member 'byteorder' of 'numpy.dtype' objects> |
char | <member 'char' of 'numpy.dtype' objects> |
descr | <attribute 'descr' of 'numpy.dtype' objects> |
fields | <attribute 'fields' of 'numpy.dtype' objects> |
flags | <member 'flags' of 'numpy.dtype' objects> |
hasobject | <attribute 'hasobject' of 'numpy.dtype' objects> |
isalignedstruct | <attribute 'isalignedstruct' of 'numpy.dtype' objects> |
isbuiltin | <attribute 'isbuiltin' of 'numpy.dtype' objects> |
isnative | <attribute 'isnative' of 'numpy.dtype' objects> |
itemsize | <member 'itemsize' of 'numpy.dtype' objects> |
kind | <member 'kind' of 'numpy.dtype' objects> |
metadata | <attribute 'metadata' of 'numpy.dtype' objects> |
name | <attribute 'name' of 'numpy.dtype' objects> |
names | <attribute 'names' of 'numpy.dtype' objects> |
ndim | <attribute 'ndim' of 'numpy.dtype' objects> |
num | <member 'num' of 'numpy.dtype' objects> |
shape | <attribute 'shape' of 'numpy.dtype' objects> |
str | <attribute 'str' of 'numpy.dtype' objects> |
subdtype | <attribute 'subdtype' of 'numpy.dtype' objects> |
type | None |
Liste des méthodes
Toutes les méthodes
Méthodes d'instance
Méthodes statiques
Méthodes dépréciées
Méthodes héritées de la classe object
__delattr__,
__dir__,
__format__,
__getattribute__,
__getstate__,
__init_subclass__,
__reduce_ex__,
__setattr__,
__sizeof__,
__subclasshook__
Vous êtes un professionnel et vous avez besoin d'une formation ?
RAG (Retrieval-Augmented Generation)et Fine Tuning d'un LLM
Voir le programme détaillé
Améliorations / Corrections
Vous avez des améliorations (ou des corrections) à proposer pour ce document : je vous remerçie par avance de m'en faire part, cela m'aide à améliorer le site.
Emplacement :
Description des améliorations :