在Numpy中执行零功能

在Numpy中执行零功能

看起来好像

calloc

达到了一个阈值，在该阈值下， *** 作系统会要求将内存清零，而无需手动对其进行初始化。查看源代码，

numpy.zeros

最终委托来

calloc

获取清零的内存块，如果与进行比较

numpy.empty

，则不执行初始化：

In [15]: %timeit np.zeros((5000, 5000))The slowest run took 12.65 times longer than the fastest. This could mean that an intermediate result is being cached.100000 loops, best of 3: 10 µs per loopIn [16]: %timeit np.empty((5000, 5000))The slowest run took 5.05 times longer than the fastest. This could mean that an intermediate result is being cached.100000 loops, best of 3: 10.3 µs per loop

您会看到

np.zeros

5000x5000阵列没有初始化开销。

实际上，在您尝试访问该内存之前，该 *** 作系统甚至没有“真正”分配该内存。在无数TB可用空间的机器上，对TB级阵列的请求成功完成：

In [23]: x = np.zeros(2**40)  # No MemoryError!