array --- Efficient arrays of numeric values¶

This module defines an object type which can compactly represent an array of basic values: characters, integers, floating-point numbers, complex numbers. Arrays are mutable sequence types and behave very much like lists, except that the type of objects stored in them is constrained. The type is specified at object creation time by using a type code. The following type codes are defined:

Notes :

1. Ajouté dans la version 3.13.

2. The IEEE 754 binary16 "half precision" type was introduced in the 2008 revision of the IEEE 754 standard. This type is not widely supported by C compilers. It's available as _Float16 type, if the compiler supports the Annex H of the C23 standard.

   Ajouté dans la version 3.15.

3. Complex types (Zf and Zd) are available unconditionally, regardless on support for complex types (the Annex G of the C11 standard) by the C compiler. As specified in the C11 standard, each complex type is represented by a two-element C array containing, respectively, the real and imaginary parts.

   Ajouté dans la version 3.15.

The actual representation of values is determined by the machine architecture (strictly speaking, by the C implementation). The actual size can be accessed through the array.itemsize attribute.

The module defines the following item:

array.typecodes¶

A tuple with all available type codes.

Modifié dans la version 3.15: The type changed from str to tuple.

Le module définit le type suivant :

class array.array(typecode[, initializer])¶

A new array whose items are restricted by typecode, and initialized from the optional initializer value, which must be a bytes or bytearray object, a Unicode string, or iterable over elements of the appropriate type.

If given a bytes or bytearray object, the initializer is passed to the new array's frombytes() method; if given a Unicode string, the initializer is passed to the fromunicode() method; otherwise, the initializer's iterator is passed to the extend() method to add initial items to the array.

Array objects support the ordinary mutable sequence operations of indexing, slicing, concatenation, and multiplication. When using slice assignment, the assigned value must be an array object with the same type code; in all other cases, TypeError is raised. Array objects also implement the buffer interface, and may be used wherever bytes-like objects are supported.

Arrays are generic over the type of their contents.

Lève un événement d'audit array.__new__ avec les arguments typecode, initializer.

typecode¶

Le code (de type Python caractère) utilisé pour spécifier le type des éléments du tableau.

itemsize¶

La longueur en octets d'un élément du tableau dans la représentation interne.

append(value, /)¶

Append a new item with the specified value to the end of the array.

buffer_info()¶

Return a tuple (address, length) giving the current memory address and the length in elements of the buffer used to hold array's contents. The size of the memory buffer in bytes can be computed as array.buffer_info()[1] * array.itemsize. This is occasionally useful when working with low-level (and inherently unsafe) I/O interfaces that require memory addresses, such as certain ioctl() operations. The returned numbers are valid as long as the array exists and no length-changing operations are applied to it.

Note

Lors de l'utilisation d'objets tableaux provenant de codes écrits en C ou C++ (le seul moyen d'utiliser efficacement ces informations), il est plus logique d'utiliser l'interface tampon supportée par les objets tableaux. Cette méthode est maintenue pour des raisons de rétrocompatibilité et devrait être évitée dans un nouveau code. L'interface tampon est documentée dans Protocole tampon.

byteswap()¶

"Byteswap" all items of the array. This is only supported for values which are 1, 2, 4, 8 or 16 bytes in size; for other types of values, RuntimeError is raised. It is useful when reading data from a file written on a machine with a different byte order. Note, that for complex types the order of components (the real part, followed by imaginary part) is preserved.

count(value, /)¶

Return the number of occurrences of value in the array.

extend(iterable, /)¶

Ajoute les éléments de iterable à la fin du tableau. Si iterable est un autre tableau, il doit le même code d'indication du type ; dans le cas contraire, TypeError sera levée. Si iterable n'est pas un tableau, il doit être itérable et ces éléments doivent être du bon type pour être ajoutés dans le tableau.

frombytes(buffer, /)¶

Appends items from the bytes-like object, interpreting its content as an array of machine values (as if it had been read from a file using the fromfile() method).

Ajouté dans la version 3.2: fromstring() is renamed to frombytes() for clarity.

fromfile(f, n, /)¶

Read n items (as machine values) from the file object f and append them to the end of the array. If less than n items are available, EOFError is raised, but the items that were available are still inserted into the array.

fromlist(list, /)¶

Ajoute les éléments de la liste. C'est l'équivalent de for x in list: a.append(x) sauf que s'il y a une erreur de type, le tableau est inchangé.

fromunicode(ustr, /)¶

Extends this array with data from the given Unicode string. The array must have type code 'w'; otherwise a ValueError is raised. Use array.frombytes(unicodestring.encode(enc)) to append Unicode data to an array of some other type.

index(value[, start[, stop]])¶

Return the smallest i such that i is the index of the first occurrence of value in the array. The optional arguments start and stop can be specified to search for value within a subsection of the array. Raise ValueError if value is not found.

Modifié dans la version 3.10: Added optional start and stop parameters.

insert(index, value, /)¶

Insert a new item value in the array before position index. Negative values are treated as being relative to the end of the array.

pop(index=-1, /)¶

Supprime l'élément du tableau avec l'index i et le renvoie. L'argument optionnel par défaut est à -1, de sorte que par défaut le dernier élément est supprimé et renvoyé.

remove(value, /)¶

Remove the first occurrence of value from the array.

clear()¶

Remove all elements from the array.

Ajouté dans la version 3.13.

reverse()¶

Inverse l'ordre des éléments du tableau.

tobytes()¶

Convertit le tableau en un tableau de valeurs machine et renvoie la représentation en octets (la même séquence d'octets qui serait écrite par la méthode tofile()).

Ajouté dans la version 3.2: tostring() is renamed to tobytes() for clarity.

tofile(f, /)¶

Écrit tous les éléments (en tant que valeurs machine) du file object f.

tolist()¶

Convertit le tableau en une liste ordinaire avec les mêmes éléments.

tounicode()¶

Convert the array to a Unicode string. The array must have a type 'w'; otherwise a ValueError is raised. Use array.tobytes().decode(enc) to obtain a Unicode string from an array of some other type.

The string representation of array objects has the form array(typecode, initializer). The initializer is omitted if the array is empty, otherwise it is a Unicode string if the typecode is 'w', otherwise it is a list of numbers. The string representation is guaranteed to be able to be converted back to an array with the same type and value using eval(), so long as the array class has been imported using from array import array. Variables inf and nan must also be defined if it contains corresponding floating-point values. Examples:

array('l')
array('w', 'hello \u2641')
array('l', [1, 2, 3, 4, 5])
array('d', [1.0, 2.0, 3.14, -inf, nan])