How could you increase the maximum recursion depth in Python?

Question

Interesting topic of recursion and stack overflow in class today and I wondered if there is any way of increasing the maximum recursion depth in Python? Wrote a quick function for finding the factorial of n using recursion:

def factorial(n):
    if n == 1:
        return n
    else:
        return n * factorial(n-1)

It can cope with factorial(994) but not factorial(995). The error given is:

RuntimeError: maximum recursion depth exceeded in comparison

Obviously a higher factorial can be found iteratively but, for the sake of argument and intrigue, can the maximum recursion depth be increased?

https://docs.python.org/2/library/sys.html#sys.setrecursionlimit — freakish, Nov 17 '15 at 13:04
Note that the standard way of avoiding too much recursion here is to use memoization. — Daniel Roseman, Nov 17 '15 at 13:05
Nope, there is no hate in here. We all are here to help others. Closing as a dupe doesn't mean that we *hate* you. All the best in future. — Bhargav Rao, Nov 17 '15 at 13:17
If implementing factorial program using recursion is necessary. You can implement it in following manner which is able to find factorial without any limit using python. https://drive.google.com/file/d/1A0z9eyXD5mNIAZRotX5RM2QAu9bbZqHa/view?usp=drivesdk — , May 16 '20 at 07:46

score 18 · Accepted Answer · answered Nov 17 '15 at 13:04

18

import sys

sys.setrecursionlimit(2000)

answered Nov 17 '15 at 13:04

Ayush

3,695
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score 6 · Answer 2 · answered Nov 17 '15 at 13:05

6

import sys

iMaxStackSize = 5000
sys.setrecursionlimit(iMaxStackSize)

answered Nov 17 '15 at 13:05

Mangu Singh Rajpurohit

10,806
4
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How could you increase the maximum recursion depth in Python?

2 Answers2