Python中的最大递归深度是多少，如何增加? [英] What is the maximum recursion depth in Python, and how to increase it?

问题描述

我在这里有这个尾递归函数:

I have this tail recursive function here:

def recursive_function(n, sum):
    if n < 1:
        return sum
    else:
        return recursive_function(n-1, sum+n)

c = 998
print(recursive_function(c, 0))

它最多可以工作到 n=997，然后它就会中断并吐出一个RecursionError:比较时超出了最大递归深度.这只是堆栈溢出吗?有没有办法绕过它?

It works up to n=997, then it just breaks and spits out a RecursionError: maximum recursion depth exceeded in comparison. Is this just a stack overflow? Is there a way to get around it?

推荐答案

它是一种防止堆栈溢出的方法，是的.Python(或者更确切地说，CPython 实现)不会优化尾递归，并且无节制的递归会导致堆栈溢出.您可以使用 sys.getrecursionlimit:

It is a guard against a stack overflow, yes. Python (or rather, the CPython implementation) doesn't optimize tail recursion, and unbridled recursion causes stack overflows. You can check the recursion limit with sys.getrecursionlimit:

import sys
print(sys.getrecursionlimit())

并使用 sys.setrecursionlimit 更改递归限制:

and change the recursion limit with sys.setrecursionlimit:

sys.setrecursionlimit(1500)

但这样做很危险——标准限制有点保守，但 Python 堆栈帧可能相当大.

but doing so is dangerous -- the standard limit is a little conservative, but Python stackframes can be quite big.

Python 不是函数式语言，尾递归也不是特别有效的技术.如果可能，迭代地重写算法通常是一个更好的主意.

Python isn't a functional language and tail recursion is not a particularly efficient technique. Rewriting the algorithm iteratively, if possible, is generally a better idea.

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