N-Bonnaci sequence calculator

The code calculates a n-bonnaci sequence to a certain number, based on the user's input. It then can print it to a file and/or print it to the console.

The calculateSequence function calculates the sequence. The first loop fills the sequence with ones (0, 1, 1, 2...). Next, it calculates the value of the current number, using crrntVlue as a placeholder, and using i as the location of the value to add (a number is the sum of the preceding two numbers). sqnceItratr is location of the number that is being calculated.

My questions are:

• Is there anything immediately wrong that you see in the code?

• How can I make the code more readable/better variable names, as it was hard to understand the code while coding it?

• How can I restructure the program to make it better?

This is one of my first Python programs, so I want to know what I might be coding 'wrong'.

```
def calculateSequence(n, amntToCalc):
sqnceItratr = 1
sequence = [0] * numbrsToCalc

#Add 1's to the array(Duonacci is 1, 1, 2... Tribonacci is 1, 1, 1, 3...)
while sqnceItratr 0:
#This is to calculate the actual value of a number
#in the sequence
crrntVlue += sequence[sqnceItratr - i]
i -= 1
#Count Down for the number to add to crrntValue(n-bonnacci)

sequence[sqnceItratr] = crrntVlue
# Add crrntValue to the array
sqnceItratr += 1
#Continue to the next value in the array
return sequence

def convertInput(inputToConvert):
inputToConvert = inputToConvert.upper()
if inputToConvert == 'Y':
return True
elif inputToConvert == 'YES':
return True
else:
return False

N = int(input("What do you want to n in N-bonnacci to be? \n"))
numbrsToCalc = int(input("How many digits do you want to calculate? \n This should probably be bigger than n \n"))
sequence = calculateSequence(N, numbrsToCalc)

userInput1 = convertInput(input("Do you want to write it to a file?

-
Algorithm

Looks like you are doing too much. The recurrence can be greatly simplified:

\$a_{n} = a_{n-1} + a_{n-2} + \cdot\cdot\cdot + a_{n-k+1} + a_{n-k}\$, and

\$a_{n+1} = a_{n} + a_{n-1} + \cdot\cdot\cdot + a_{n-k+1}\$, so

\$a_{n+1} = a_{n} + (a_{n-1} + \cdot\cdot\cdot + a_{n-k+1}) = a_{n} + (a_{n} - a_{n-k})\$

meaning that the next k-bonacchi number is just

sequence[n+1] = 2*sequence[n] + sequence[n-k]

-
Naming

Honestly, names like sqnceItratr and crrntVlue are more than unreadable. Don't abbreviate so aggressively. In this particular case I'd say that n fits much better than sqnceItratr.

-
Separation of concerns

calculateSequence initialize the sequence and produces the rest of it in a single call. It doesn't look right. I recommend to split the solution in initialize, and compute_next calls, along the lines of

sequence = initialize(N)
for n in range(N, limit):
    value = compute_next(sequence, N)
    sequence.append(value)

StackExchange Code Review Q#119239, answer score: 4