Find the highest number of divisors between range in python?

Question

I am new to python, I am giving two numbers,

a = 2
b = 9

a and b are inclusive range i.e; (2,3,..,9). and my expectation for highest number of divisors are 6 and 8.

Solution Explanation:

 4 = 2 * 2(one factor)
 6 = 2 * 3(two factor)
 8 = 2 * 4(two factor)
 9 = 3 * 3(one factor)

So, Need to Choose highest number of factors.

How to list the highest number of divisors in python from above logic ?.

Ex:

If I give the range (1,2,..,10). Then it should gave the result of highest number of divisors are 6,8 and 10.

and so on..

http://stackoverflow.com/questions/6800193/what-is-the-most-efficient-way-of-finding-all-the-factors-of-a-number-in-python — Fredrik Pihl, Dec 13 '13 at 11:38
Also, what have you tried? We don't simply write your code for you, we help you fix your own — yuvi, Dec 13 '13 at 11:58
This is obviously a homework/assignment question and the problem and solution is well understood and all over the internet and in classical programming texts. — James Mills, Dec 13 '13 at 12:11

Games Brainiac · Accepted Answer · 2013-12-13T12:31:25.487

0

This perhaps is what you're looking for:

import operator


def higest_divisors(a, b):
    _ret = {var: len([x for x in range(a, b+1) if not var % x]) for var in range(a, b+1)}.items()
    max = 0
    _to_ret = []
    for n, t in sorted(_ret, key=operator.itemgetter(1))[::-1]:
        if max <= t:
            _to_ret.append(n)
            max = t

    return _to_ret

if __name__ == '__main__':
    print higest_divisors(2, 10)

EDIT

This looks a lot better:

from itertools import takewhile
import operator


def highest_divisors(a, b):
    _divisors = sorted({var: len([x for x in range(a, b + 1) if not var % x])
                        for var in range(a, b + 1)}.iteritems(),
                       key=operator.itemgetter(1))[::-1]
    _max = _divisors[0][1]
    return [n for n, v in takewhile(lambda y: y[1] == _max, _divisors)]


if __name__ == '__main__':
    for var in highest_divisors(2, 10):
        print var

edited Dec 13 '13 at 12:31

answered Dec 13 '13 at 12:07

Games Brainiac

80,178
33
141
199

Horrible code, I know, but its still a work in progress :P – Games Brainiac Dec 13 '13 at 12:07
1

Seriously? naming a variable as `max`? ;) – thefourtheye Dec 13 '13 at 12:07
@thefourtheye not a complete disaster for a local variable :) – alko Dec 13 '13 at 12:08
@thefourtheye I _did_ say its a work in progress :D – Games Brainiac Dec 13 '13 at 12:10
@thefourtheye Do you like the _newer_ version more? – Games Brainiac Dec 13 '13 at 12:25
@GamesBrainiac Sorry. Looks inefficient to me :( – thefourtheye Dec 13 '13 at 12:42
@thefourtheye Shouldn't be. Its done in a dictionary comprehension and list comprehension, it should be quite fast. – Games Brainiac Dec 13 '13 at 12:44

Find the highest number of divisors between range in python?

1 Answers1

EDIT