Python3 sudoku return problems

Question

With the code below I can check rows and columns to see if the Sudoku program is set up correctly, however; the function returns two answers for checkIt (rows and cols). Is there a way to set up the code to check both rows and cols and then return with "This Sudoku solution is correct!" if both happen to be correct(True) along with being able to return with "Error in column/row (.append(number))" if either row/col checkIt function solution happened to be incorrect(False)?

import sys
from scanner import *

def createList(size):
    if size == 0: return []
    else:
        return [0] + createList(size -1)
def printGrid(gridlist):
    for row in gridlist:
       print (str(row)+"\n")
def rows(g):
    return len(g)
def cols(g):
    return len(g[0])

def printMatrix(g):
    for i in range(0,rows(g),1):
        for j in range(0,cols(g),1):
            print(g[i][j],end=' ')
        print('')
    print('')

def readinput(filename,grid):
    s = Scanner(filename)
    r = s.readtoken()
    while r != "":
        r = int(r)
        c = s.readint()
        v = s.readint()
        grid[r][c]=v
        r = s.readtoken()

def checkRows(g):
    for rows in g:
        numbersInRow = []
        for number in rows:
            if number != 0 and number in numbersInRow:
                return g.index(rows),False
            else:
                numbersInRow.append(number)
    return "This Sudoku solution is correct!"

def checkCols(g):
    for cols in g:
        numbersInCol = []
        for number in cols:
            if number != 0 and number in numbersInCol:
                return g.index(cols),False
            else:
                numbersInCol.append(number)
    return True

def checkIt(g):
    checkRows(g)
    rowSuccess = checkRows(g)
    print(rowSuccess)
    checkCols(g)
    colSuccess = checkCols(g)
    print(colSuccess)

def main():
    grid = createList(9)
    for i in range(9):
        grid[i] = createList(9)
    readinput(sys.argv[1],grid)
    printMatrix(grid)
    checkIt(grid)
main()

yes, but im supposed to check each conflict step by step, Rows and Cols were firs, then subgrid comes next — user3754670

djbhindi djbhindi · Accepted Answer · 2014-06-24T01:19:28

def checkIt(g):
   rows = checkRows(g)
   cols = checkCols(g)
   if rows == "good" and cols == "good":
       print(rowSuccess, colSuccess)
   elif rows=="good":
       print("Error in col: " + cols)
   elif cols=="good":
       print("Error in row: " + rows)
   else: # Both rows and cols have an error
       print("Error in row: " + rows)
       print("\nError in col: " + cols)

EDIT: With regards to comment below: Try returning a list of error positions if error(s) come up (just append an error to the list when it comes up). At the end, if the list is of size 0 (no errors) just return True

Simply have checkRows(g) and checkCols(g) return "good" if everything is fine and the number of the row/column where the error is if an error comes up.

Python3 sudoku return problems

2 Answers