0

please help!

I keep getting this error : (-3, -3, IndexError('list index out of range',))

class SokobanProblem(search.Problem):

```
def __init__(self, initial): ##-------- creates an object of the class ##
tmp_list = list(initial)
row_len = len(tmp_list)
column_len = len(tmp_list[0])-1
goal_list = []
for i in xrange(0, row_len):
tmp = list(tmp_list[i])
goal_list.append(tmp)
goal_tuple = ()
for i in xrange(0, row_len):
for j in xrange(0, column_len):
if goal_list[i][j] == 1 :
goal_list[i][j] = 5
if goal_list[i][j] == 3 :
goal_list[i][j] = 5
if goal_list[i][j] == 4 :
goal_list[i][j] = 0
if goal_list[i][j] == 2 :
goal_list[i][j] = 0
goal_list[i] = tuple(goal_list[i])
goal_tuple = tuple(goal_list)
search.Problem.__init__(self, initial, goal_tuple)
def successor(self, state): ##-------- creates an object of the class ##
row_len = len(state)
column_len = len(state[0])-1
successors = []
list_state = []
tmp_list = list(state)
for i in xrange(0, row_len):
tmp = list(tmp_list[i])
list_state.append(tmp)
for i in xrange(0, row_len):
for j in xrange(0, column_len):
if (list_state[i][j] == 2 or list_state[i][j] == 3) :
#"UP" option
if ((i-1) >= 0 and (list_state[i-1][j] == 0 or list_state[i-1][j] == 1)):
state_up =copy.deepcopy(list_state)
state_up[i-1][j] = state_up[i-1][j] +2
state_up[i][j] = state_up[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_up[i] = tuple(state_up[i])
tuple_state = tuple(state_up)
successors.append(["U", tuple_state])
if (((i-2) >= 0) and (list_state[i-1][j] == 4) and ((list_state[i-2][j] == 0) or (list_state[i-2][j] == 1))):
state_up =copy.deepcopy(list_state)
state_up[i-2][j] = state_up[i-2][j] +4
state_up[i-1][j] = state_up[i-1][j] -2
state_up[i][j] = state_up[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_up[i] = tuple(state_up[i])
tuple_state = tuple(state_up)
successors.append(["U", tuple_state])
#"DOWN" option
if ((i+1) < row_len and (list_state[i+1][j] == 0 or list_state[i+1][j] == 1)):
state_down =copy.deepcopy(list_state)
state_down[i+1][j] = state_down[i+1][j] +2
state_down[i][j] = state_down[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_down[i] = tuple(state_down[i])
tuple_state = tuple(state_down)
successors.append(["D", tuple_state])
if (((i+2) < row_len) and (list_state[i+1][j] == 4) and ((list_state[i+2][j] == 0) or (list_state[i+2][j] == 1))):
state_down =copy.deepcopy(list_state)
state_down[i+2][j] = state_down[i+2][j] +4
state_down[i+1][j] = state_down[i+1][j] -2
state_down[i][j] = state_down[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_down[i] = tuple(state_down[i])
tuple_state = tuple(state_down)
successors.append(["D", tuple_state])
#"LEFT" option
if ((j-1) >= 0 and (list_state[i][j-1] == 0 or list_state[i][j-1] == 1)):
state_left =copy.deepcopy(list_state)
state_left[i][j-1] = state_left[i][j-1] +2
state_left[i][j] = state_left[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_left[i] = tuple(state_left[i])
tuple_state = tuple(state_left)
successors.append(["L", tuple_state])
if (((j-2) >= 0) and (list_state[i][j-1] == 4) and ((list_state[i][j-2] == 0) or (list_state[i][j-2] == 1))):
state_left =copy.deepcopy(list_state)
state_left[i][j-2] = state_left[i][j-2] +4
state_left[i][j-1] = state_left[i][j-1] -2
state_left[i][j] = state_left[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_left[i] = tuple(state_left[i])
tuple_state = tuple(state_left)
successors.append(["L", tuple_state])
#"RIGHT" option
if ((j+1) < column_len and (list_state[i][j+1] == 0 or list_state[i][j+1] == 1)):
state_right =copy.deepcopy(list_state)
state_right [i][j+1] = state_right [i][j+1] +2
state_right [i][j] = state_right[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_right[i] = tuple(state_right[i])
tuple_state = tuple(state_right)
successors.append(["R", tuple_state])
if (((j+2) < column_len) and (list_state[i][j+1] == 4) and ((list_state[i][j+2] == 0) or (list_state[i][j+2] == 1))):
state_right =copy.deepcopy(list_state)
state_right[i][j+2] = state_right[i][j+2] +4
state_right[i][j+1] = state_right[i][j+1] -2
state_right[i][j] = state_right[i][j] -2
tuple_state = ()
for i in xrange(0, row_len):
state_right[i] = tuple(state_right[i])
tuple_state = tuple(state_right)
successors.append(["R", tuple_state])
successors_tuple = ()
for i in xrange(0,4):
successors[i] = tuple(successors[i])
successors_tuple = tuple(successors)
return successors_tuple
def goal_test(self, state):
row_len = len(state)
column_len = len(state[0])-1
state_list = []
tmp_state = list(state)
state_tuple = ()
for i in xrange(0, row_len):
tmp = list(tmp_state[i])
state_list.append(tmp)
for i in xrange(0, row_len):
for j in xrange(0, column_len):
if (state_list[i][j] == 2):
state_list[i][j] = 0
state_list[i] = tuple(state_list[i])
state_tuple = tuple(state_list)
return state_tuple == self.goal
def create_sokoban_problem(game):
sokoban_problem=SokobanProblem(game)
return sokoban_problem
```

any suggestions?

any help will be much appreciated !