How to improve the quality of my code?

[grobattac37]

Here is some code I wrote that finds some values: a,b,c,d,e, that satisfy some expression. I would like to know: how I could shorten this code (perhaps using a list comprehension?), how I could make the code more readable, if there is a more efficient way to do this, and any other tips you could give me. Any criticism is welcome as long as you also tell me how to address the criticism. Thanks!

nums = [2,3,5,7,9]
for a in nums:
    for b in nums:
        for c in nums:
            for d in nums:
                for e in nums:
                    x = a + b * c**2 + d**3 - e
                    if x == 399:
                        print(a,b,c,d,e)

P.S. This code was written to complete a task in the synacor challenge, I recommend it if you have some spare time and want to test your skills. (I am stuck on the teleport task so any hints for that would also be appreciated).

[perfringo]

I have no idea what synacor challange is. As I understand there is a list, some calculations should be performed with list elements and result is compared to 399. If result is equal to 399 then list elements are printed separated by space.

One can take advantage of indices:

>>> nums = [2,3,5,7,9]
>>> if nums[0] + nums[1] * nums[2] ** 2 + nums[3] ** 3 - nums[4] == 399:
...     print(*nums, sep=' ')

For readability purposes one can use unpacking:

>>> nums = [2,3,5,7,9]
>>> a, b, c, d, e = nums
>>> if a + b * c**2 + d**3 - e == 399:
...     print(*nums, sep=' ')

To improve readability even more one can move calculation under name (this can also be combined with unpacking):

>>> nums = [2,3,5,7,9]
>>> result = nums[0] + nums[1] * nums[2] ** 2 + nums[3] ** 3 - nums[4]
>>> if result == 399:
...     print(*nums, sep=' ')

[buran]

Have a look at itertools.product()

from itertools import product

nums = [2,3,5,7,9]
for a, b, c, d, e in product(nums, repeat=5):
    if a + b * c**2 + d**3 - e == 399:
        print(a,b,c,d,e)

[ichabod801]

It seems like some search pruning would be useful here. It's possible that b * c ** 2 > 399 or d ** 3 > 399. In which case you don't need to check the combinations of the other values. You are subtracting e, but you could just move the threshold to 408 to cover that. The problem is that itertools.product is going to be faster than doing the loops yourself. I'm not sure you can save enough time with search pruning to outweigh the speed benefits of product.