check_sudoku

# Define a procedure, check_sudoku,# that takes as input a square list# of lists representing an n x n# sudoku puzzle solution and returns the boolean# True if the input is a valid# sudoku square and returns the boolean False# otherwise.# A valid sudoku square satisfies these# two properties:#   1. Each column of the square contains#       each of the whole numbers from 1 to n exactly once.#   2. Each row of the square contains each#       of the whole numbers from 1 to n exactly once.# You may assume the the input is square and contains at# least one row and column.def rowcheck(l):    sign=1    for i in l:        original=[1,2,3,4,5,6,7,8,9]        p=original[:len(l)]        for j in p:            if j not in i:                sign=-1                break            else:                pos = i.index(j)                k=i[pos+1:]                if j in k:                    sign=-1                    break          if sign==1:        return True    else:        return False       def colcheck(l):    i=0    p=l+[1,3,3]    while i<len(l):        j=0        while j<len(l):            l[i][j]=p[j][i]            j=j+1        i=i+1    return rowcheck(l)def check_sudoku(a):    if rowcheck(a)==True and colcheck(a)==True:        return True    else:        return False