如何减少 Cython 编译代码与 Python 的交互

Question

我试图通过使用 Cython 编译为 C 来减少计算量特别大的 Python 代码。令人惊讶的是，我在加速它方面几乎没有成功。使用原始 Python 模块，代码运行时间约为 45 秒，使用 Cython 编译模块运行时间约为 45 秒。

使用 annotate=True 编译时，我留下了一大堆黄色（ish）行，表明仍然存在大量 Python 交互。

我已通过关闭boundscheck (False) 和cdivision (True) 对此作出回应。这没有效果。下面的 sn-p 代码是从这个模块中提取的，它坚持与 Python 交互。为什么是这样？这里不需要与任何预先存在的 Python 模块交互，都是非常简单的算术运算？

cpdef float __distance_between(point1, point2)  except? -2:
    return ((point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2) ** (1/2)

point1 和 point2 是 Python 列表，每个列表都包含 2 个 doubles 例如：[611811.997, -871083.372] Cython 为 sn-p 中的 return 行生成的 C 代码为如下：

+05: cpdef float __distance_between(point1, point2)  except? -2:
+06:     return ((point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2)**(1/2)
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如何更好地优化代码或编译以使这个 sn-p 独立于 Python？

此模块中还有许多其他行都呈现为黄色，但从这个问题开始可能会让我更好地了解如何解决其余问题。

Answer 1

您还没有cdefed 任何变量； 你知道他们是float，Cython 不知道。告诉它。

cpdef float __distance_between((double, double)point1, (double, double)point2)  except? -2:
    return ((point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2) ** (1/2)