Sudoku solver.Working on solving that bottom left three

Sudoku solver.Working on solving that bottom left three

import numpy

#Build our possibilities matrix
global possibilities, solved
possibilities = numpy.ndarray((9,9,9))
solved = numpy.ndarray((9,9))

i = list(range(9))
j = list(range(9))
for x in i:
    for y in j:
        possibilities[x][y] = list(range(10))[1:]

#Set our starting game
easy = '017002560034015080009000140450000600020781090008000021096000200080470950045200810'
#Medium
#Hard
#Very Hard
stuck = '000500836058300127103070495501000000006090700000000208972030001000008370800007000'
level = stuck
i=0

for block in level:
    if block != '0':
        x, y = divmod(i, 9)
        possibilities[x][y] = 0
        possibilities[x][y][int(block)-1] = int(block)
    i+=1
i=0

for block in level:
  x, y = divmod(i, 9)
  if block != '0':
    solved[x][y] = 1
  else:
    solved[x][y] = 0
  i+=1

def iter_square(i, silence=False):
  key_blocks = [0,3,6,27,30,33,54,57,60]
  x,y = divmod(key_blocks[i], 9)
  for j in range(3):
    for k in range(3):
      if not silence: print(x+j, y+k)
      yield(x+j, y+k)

def square_elim():
  for i in range(9):
    for blockx, blocky in iter_square(i):
      if solved[blockx][blocky] == 1:
        j=0
        for item in possibilities[blockx][blocky]:
          if item !=0.:
            for blocka, blockb in iter_square(i, silence=True):
              if (blocka, blockb) != (blockx, blocky):
                possibilities[blocka][blockb][j] = 0.
          j+=1
    #break

def rows_cols():
    for x in range(9):
      for y in range(9):
        if solved[x][y] == 1:
          print('Solved at:')
          print(x, y)
          i=0
          for item in possibilities[x][y]:
            if item !=0.:
                for a in range(9):
                    if (a, y) != (x, y):
                        possibilities[a][y][i]=0
                for a in range(9):
                    if (x, a) != (x, y):
                        possibilities[x][a][i]=0
            i+=1

def rows_cols_two_strike():
    pass

def check_solved():
  new_solves = 0
  for x in range(9):
    for y in range(9):
      if solved[x][y] == 0:
        temp = set(possibilities[x][y])
          solved[x][y] = 1
          new_solves += 1
  return new_solves

def row_elims():
    pass

def complex_solves():
    row_elims()

while(True):
  #cheap logic goes here
  square_elim()
  rows_cols()
  new_solves = check_solved()
  #more expensive logic goes here...
  if new_solves == 0:
    complex_solves()
    new_solves = check_solved()
    if new_solves == 0:
      print('Finished playing.  Either got stuck or won.')
      print(solved)
      break