如何使用python构建一个intarray，并将其与C语言一样高效？

Question

来自http://www.cs.bell-labs.com/cm/cs/pearls/sol01.html：

C代码是这样的：

#define BITSPERWORD 32
#define SHIFT 5
#define MASK 0x1F
#define N 10000000
int a[1 + N/BITSPERWORD];

void set(int i) {        a[i>>SHIFT] |=  (1<<(i & MASK)); }
void clr(int i) {        a[i>>SHIFT] &= ~(1<<(i & MASK)); }
int  test(int i){ return a[i>>SHIFT] &   (1<<(i & MASK)); }

我找到了ctypes，BitArrays，numpy，但我不确定它们是否能像上面的C代码那样高效。在

例如，如果我写这样的代码：

^{pr2}$

使用的空间是1M字节还是更多？在

有人知道一些好的库可以用Python做同样的事情吗？在

Answer 1

您还可以检查内置的array模块：

>>> import array
>>> help(array)
Help on built-in module array:

NAME
    array

FILE
    (built-in)

DESCRIPTION
    This module defines an object type which can efficiently represent
    an array of basic values: characters, integers, floating point
    numbers.  Arrays are 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, which
    is a single character.  The following type codes are defined:

        Type code   C Type             Minimum size in bytes 
        'b'         signed integer     1 
        'B'         unsigned integer   1 
        'u'         Unicode character  2 (see note) 
        'h'         signed integer     2 
        'H'         unsigned integer   2 
        'i'         signed integer     2 
        'I'         unsigned integer   2 
        'l'         signed integer     4 
        'L'         unsigned integer   4 
        'f'         floating point     4 
        'd'         floating point     8