Range is too large Python

Question

I\'m trying to find the largest prime factor of the number x, Python gives me the error that the range is too large. I\'ve tried using x range but I get an OverflowError: Py

Answer 1

In old (2.x) versions of Python, xrange can only handle Python 2.x ints, which are bound by the native long integer size of your platform. Additionally, range allocates a list with all numbers beforehand on Python 2.x, and is therefore unsuitable for large arguments.

You can either switch to 3.x (recommended), or a platform where long int (in C) is 64 bit long, or use the following drop-in:

import itertools
range = lambda stop: iter(itertools.count().next, stop)

Equivalently, in a plain form:

def range(stop):
   i = 0
   while i < stop:
       yield i
       i += 1