RodCutting and learning Dynamic Programming

Question

I tried to learn dynamic programming going from recursion to memoized version with the RodCutting problem: Returns the best obtainable price for a rod of length n and price[] as prices of different pieces.

Have you any suggestions on the code (or the way to make test), i tried to keep as simple and generic to mimic on others similar problems (i could have erase the n from input and calculate inside the function but it would confuse the solution).

"""
Inspiration of DP from: https://wellsr.com/python/optimizing-recursive-functions-with-python-memoization/
"""
def cutRod(price, n):
 """
 Returns the best obtainable price for a rod of length n
 and price[] as prices of different pieces
 """
 res = price[n-1] # One piece without cut
 for i in range(n-1):
 res = max(res,price[i]+cutRod(price,n-(i+1))) #i+1 cut
 return res
def cutRodMemo(price, n):
 """
 Returns the best obtainable price for a rod of length n
 and price[] as prices of different pieces
 """
 # 1.Define memo table
 memo = [None]*n
 memo[0] = price[0]
 # 2.Memoize recursive approach
 def cutRodAux(price,n,memo):
 if memo[n-1]:
 return memo[n-1]
 res = price[n-1]
 for i in range(n-1):
 res = max(res,price[i]+cutRodAux(price,n-(i+1),memo)) 
 memo[n-1]= res
 return res
 return cutRodAux(price,n,memo)
if __name__ == '__main__':
 import unittest
 f = cutRod
 class Test(unittest.TestCase):
 def test(self): 
 args = [(([10,24,30,40],4),48),
 (([1, 5, 8, 9, 10, 17, 17, 20],8),22)
 ]
 for i,o in args:
 prices,size = i
 self.assertEqual(cutRod(prices,size), o)
 self.assertEqual(cutRodMemo(prices,size), o)
 
 unittest.main()
 

Answer 1

1. Don't put tests in the same file as the main script
2. f = cutRod - f seems unused
3. Defining a function right in the middle of another one isn't very pretty. Move it up to the beggining or preferrably make a separate function altogether.
4. Removing n from the input would actually be a good idea as right now you are providing redundant information.