redmond python problem

def check(t, depth, myrange):
    #print('checking ' + str(t))
    #print (' depth = ' + str(depth))
    if t is None:
        return True
    left_range_list = []
    if not check(t[0],depth+1,left_range_list):
        return False
    right_range_list = []
    if not check(t[2],depth+1,right_range_list):
        return False
    myrange.append([t[1],t[1]])
    for i in range(max(len(left_range_list),len(right_range_list))):
        if i < len(left_range_list):
            left_range = left_range_list[i]
        else:
            left_range = None
        if i < len(right_range_list):
            right_range = right_range_list[i]
        else:
            right_range = None
        if left_range is None:
            myrange.append(right_range)
        elif right_range is None:
            myrange.append(left_range)
        else:
            range_evenness = (i+depth+1)%2
            #print('merging ' + str(left_range) + ' with ' + str(right_range) + ' at ' + str(range_evenness) + ' evenness')
            if left_range[1] == right_range[0] or \
               (left_range[1] > right_range[0]) != (range_evenness == 0):
                #print('left and right in wrong order')
                return False
            #print('merge ok')
            myrange.append([left_range[0],right_range[1]])
    return (depth % 2 != t[1] % 2)

ranges = []
print('check 1 = ' + str(check([[[None,9,None],2,[None,7,None]],1,[[None,5,None],4,[None,3,None]]],0,ranges)))
print('ranges = ' + str(ranges))
ranges = []
print('check 2 = ' + str(check([[[None,9,None],2,[None,5,None]],1,[[None,7,None],4,[None,3,None]]],0,ranges)))
print('ranges = ' + str(ranges))
ranges = []
print('check 3 = ' + str(check([[[None,9,None],2,[None,7,None]],1,[[None,5,None],4,None]],0,ranges)))
print('ranges = ' + str(ranges))
ranges = []
print('check 4 = ' + str(check([[[None,9,None],2,[None,7,None]],1,[[None,5,None],5,[None,3,None]]],0,ranges)))
print('ranges = ' + str(ranges))