Python 大量崩溃

Question

我是 Python 的新手，但我遇到了递归创建斐波那契生成器的挑战，让我开始学习这门语言。问题是，如果我发现超过 3226/3227 个斐波那契数，Python 就会崩溃。 ( python 3)

注意:我用 PHP、JavaScript 做过很多编程，用过一点 VBA，用过一点 Java，但我对 Python 完全陌生。因此，如果这只是错误的数据类型或其他问题，我真的很抱歉。

import sys
sys.setrecursionlimit(1000000000)

cache = dict()

 def fibonacci(n, arr = False):
    global cache

    if n == 0 or n == 1:
         r = n
    else:
        nVal1 = n - 1
        nVal2 = n - 2
        if (not nVal1 in cache):
            num1 = cache[nVal1] = fibonacci(nVal1, arr)
        else:
            num1 = cache[nVal1]
        if (not nVal2 in cache):
            num2 = cache[nVal2] = fibonacci(nVal2)
        else:
            num2 = cache[nVal2]

        r = num1 + num2


     if arr != False:
        arr.append(r)


    return r

fib = list()
# 3227 is max without generating a list.
# 3226 is max when generating a list.
fibonacci(3226, fib)
for x in fib: print(x)

我该怎么做才能让它走得更远？我不认为它已经耗尽内存，因为它在我的慢速 i3 笔记本电脑上运行了大约两秒钟......

Answer 1

阅读来自 sys.setrecursionlimit 的笔记

The highest possible limit is platform-dependent. A user may need to set the limit higher when she has a program that requires deep recursion and a platform that supports a higher limit. This should be done with care, because a too-high limit can lead to a crash.

我会这样实现 fibo

def fib():
    a,b = 1,0
    while True:
        yield a
        b = a+b
        yield b
        a = a+b

fibs = fib()
fibo = [next(fibs) for i in xrange(100)]