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:

Notas:

1. Puede ser de 16 bits o 32 bits según la plataforma.

   Distinto en la versión 3.9: array('u') now uses wchar_t as C type instead of deprecated Py_UNICODE. This change doesn’t affect its behavior because Py_UNICODE is alias of wchar_t since Python 3.3.

   Deprecated since version 3.3, will be removed in version 3.16: Please migrate to 'w' typecode.

2. Added in version 3.13.

3. 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.

   Added in version 3.15.

4. 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.

   Added in 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.

Distinto en la versión 3.15: The type changed from str to tuple.

El módulo define los siguientes tipos:

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.

Lanza un evento de auditoría array.__new__ con argumentos typecode, initializer.

typecode¶

El carácter typecode utilizado para crear el arreglo.

itemsize¶

La longitud en bytes de un elemento del arreglo en su representación interna.

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.

Nota

Cuando utilizamos objetos tipo arreglo escritos en C o C++ (la única manera de utilizar esta información de forma más efectiva), tiene más sentido utilizar interfaces buffer que soporten objetos del tipo arreglo. Este método es mantenido con retro compatibilidad y tiene que ser evitado en el nuevo código. Las interfaces de buffer son documentadas en Protocolo búfer.

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, /)¶

Añade los elementos del iterable al final del arreglo. Si el iterable es de otro arreglo, este debe ser exactamente del mismo tipo; si no, se lanza TypeError. Si el iterable no es un arreglo, este debe de ser un iterable y sus elementos deben ser del tipo correcto para ser añadidos al arreglo.

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).

Added in version 3.2: fromstring() is renamed to frombytes() for clarity.

fromfile(f, n, /)¶

Lee n elementos (como valores de máquina) del file object f y los añade al final del arreglo. Si hay menos de n elementos disponibles, se lanza EOFError, pero los elementos que estaban disponibles todavía se insertan en el arreglo.

fromlist(list, /)¶

Añade los elementos de la lista. Es equivalente a for x in list: a.append(x) excepto que si hay un error de tipo, el arreglo no se modifica.

fromunicode(ustr, /)¶

Extends this array with data from the given Unicode string. The array must have type code 'u' or '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.

Distinto en la versión 3.10: Se agregaron parámetros opcionales start y stop.

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, /)¶

Elimina el elemento con índice i del arreglo y lo retorna. El argumento opcional por defecto es -1, en caso de utilizar el argumento por defecto el ultimo elemento es eliminado y retornado.

remove(value, /)¶

Remove the first occurrence of value from the array.

clear()¶

Remove all elements from the array.

Added in version 3.13.

reverse()¶

Invierte el orden de los elementos en el arreglo.

tobytes()¶

Convierte el arreglo en un arreglo de valores máquina y retorna una representación en formato de bytes (la misma secuencia de bytes que se deben escribir en un fichero por el método tofile().)

Added in version 3.2: tostring() is renamed to tobytes() for clarity.

tofile(f, /)¶

Escribe todos los elementos (incluido elementos máquina) a el file object f.

tolist()¶

Convierte el arreglo a una lista ordinaria con los mismos elementos.

tounicode()¶

Convert the array to a Unicode string. The array must have a type 'u' or '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 'u' or '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])