def version_2(test):
(given, expected) = test
original_stack = Stack()
sorted_stack = Stack()
for g in given:
original_stack.push(g)
# starts here
num_eltos = original_stack.size
for i in range(num_eltos):
pivot = original_stack.pop()
num_swaps = 0
while (not sorted_stack.is_empty()) and (pivot < sorted_stack.peek()):
original_stack.push(sorted_stack.pop())
num_swaps += 1
sorted_stack.push(pivot)
for _ in range(num_swaps):
sorted_stack.push(original_stack.pop())
# sorts in reverse order (smallest on top)
while not sorted_stack.is_empty():
original_stack.push(sorted_stack.pop())
given_str = ''.join(original_stack.to_array()) # doesn't count in the O(.) calculation
return given_str == expected
class MyQueue:
def __init__(self):
self.front = Stack()
self.end = Stack()
def size(self):
return self.front.size() + self.end.size()
def enqueue(self, val):
self.end.push(val)
def dequeue(self):
if self.front.is_empty() and not self.move():
raise Exception("queue is empty")
return self.front.pop()
def peek(self):
if self.front.is_empty() and not self.move():
raise Exception("queue is empty")
return self.front.peek()
# time: O(n), however, the average is O(1)
def move(self):
moved = False
while not self.end.is_empty():
moved = True
self.front.push(self.end.pop())
return moved
def print_q(self):
print self.front
print self.end
def dft(self, starting_vertex: T) -> None:
"""
Print each vertex in depth-first order
beginning from starting_vertex.
"""
# keep track of visited vertices
visited = set()
# create a stack class
stack = Stack()
# push the starting vertex onto the stack
stack.push(starting_vertex)
# while stack is not empty
while stack.size():
# pop from the stack
current_vertex = stack.pop()
# if current vertex has not been visited
if current_vertex not in visited:
# add it to visited
visited.add(current_vertex)
# print the current vertex
print(current_vertex)
# for every neighbors of current_vertex
for vertex in self.vertices[current_vertex]:
# push it onto the stack
stack.push(vertex)
def dfs(self, starting_vertex, destination_vertex):
"""
Return a list containing a path from
starting_vertex to destination_vertex in
depth-first order.
"""
# make a stack
stack = Stack()
# make a visited set
visited = set()
# push the PATH to that node
stack.push([starting_vertex])
# while the stack isn't empty
while stack.size():
# pop the PATH
path = stack.pop()
# the last thing in the path is our current item
node = path[-1]
# if node is not visited:
if node not in visited:
# CHECK if it is the target
if node == destination_vertex:
return path
visited.add(node)
for neighbor in self.vertices[node]:
#copy the path
PATH_COPY = path.copy()
# add neighbor to the path
PATH_COPY.append(neighbor)
# enqueue the PATH_COPY
stack.push(PATH_COPY)
return None
def depth_first(self, xy1, xy2):
"""Execute a depth first search."""
tile_col1, tile_row1 = self.the_map.xy_to_cr(xy1[0], xy1[1])
tile_col2, tile_row2 = self.the_map.xy_to_cr(xy2[0], xy2[1])
successor_to_parent_map = {}
start_state = (tile_col1, tile_row1)
successor_to_parent_map[(
start_state,
None)] = None # (Successor, Action) -> (Parent, Action)
open_list = Stack()
open_list.push((start_state, None))
closed = []
while not open_list.isEmpty():
current_state, action_to_current_state = open_list.pop()
if current_state == (tile_col2, tile_row2):
return self.__get_action_path(
(current_state, action_to_current_state),
successor_to_parent_map)
if current_state not in closed:
for successor_state, action, step_cost in self.__get_successors(
current_state):
open_list.push((successor_state, action))
if successor_state not in closed:
successor_to_parent_map[(successor_state, action)] = (
current_state, action_to_current_state)
closed.append(current_state)
return []
def path_to(self, v):
if not self.has_path_to(v):
return None
edges = Stack()
e = self.edgeTo[v]
while e is not None:
edges.push(e)
e = self.edgeTo[e.From()]
return edges
def traverse(world, traversal_path):
# iterating through all rooms as unknown
def is_unknown(graph):
for k in graph:
if '?' in graph[k].values():
return True
return False
def find_new_move(visited, current_room):
curr_room = current_room.id
room_exits = visited[curr_room]
for direction in room_exits:
if room_exits[
direction] == '?' and current_room.get_room_in_direction(
direction).id not in visited:
return direction
return None
def find_new_room(traversal_path, visited, curr_room, stack, reverse):
while True:
next_move = stack.pop()
traversal_path.append(next_move)
next_room = curr_room.get_room_in_direction(next_move)
if '?' in visited[next_room.id].values():
return next_room.id
curr_room = next_room
stack = Stack()
curr = 0
visited = {0: {}}
curr_room = world.rooms[curr]
reverse = {'n': 's', 'e': 'w', 's': 'n', 'w': 'e'}
for direction in curr_room.get_exits():
visited[curr_room.id][direction] = '?'
while len(visited) < len(world.rooms) and is_unknown(visited):
curr_room = world.rooms[curr]
if curr_room not in visited:
visited[curr_room.id] = {}
for direction in curr_room.get_exits():
visited[curr_room.id][direction] = '?'
next_move = find_new_move(visited, curr_room)
if not next_move:
curr = find_new_room(traversal_path, visited, curr_room, stack,
reverse)
else:
traversal_path.append(next_move)
next_room = curr_room.get_room_in_direction(next_move)
visited[curr][next_move] = next_room.id
if next_room.id not in visited:
visited[next_room.id] = {}
for direction in next_room.get_exits():
visited[next_room.id][direction] = '?'
visited[next_room.id][reverse[next_move]] = curr_room.id
stack.push(reverse[next_move])
curr = next_room.id
def trace_cycle(self, v, w):
stack = Stack()
x = v
while x != w:
stack.push(x)
x = self.edge_to[x]
stack.push(w)
stack.push(v)
return stack
def earliest_ancestor(ancestors, starting_node, visited=None, path=None):
# initialize path = [starting_node]
# path = [starting_node]
# get parents - only care about parent not starting node i.e: node[1]
# loop to check for number of connections
# if no connections return -1
print('ancestors:', ancestors)
print('starting_node:', starting_node)
graph = Graph()
stack = Stack()
path = [starting_node]
stack.push(path)
graph = {}
for key, value in ancestors:
# print('k,v:',key, value)
if value not in graph:
# print('aa',value)
graph[value] = set()
if key not in graph:
print('aa', value)
graph[key] = set()
graph[value].add(key)
print('graph:', graph)
if len(graph[starting_node]) == 0:
return -1
visited = set()
paths = list()
print('paths:', paths)
while stack.size() > 0:
current_path = stack.pop()
print('current_path:', current_path)
current_node = current_path[-1]
print('current_node:', current_node)
if current_node not in visited:
visited.add(current_node)
print('visited', visited)
for parent in graph[current_node]:
if parent not in visited:
new_path = list(current_path)
new_path.append(parent)
print('new_path:', new_path)
stack.push(new_path)
if len(graph[current_node]) == 0:
paths.append(current_path)
print('paths:', paths)
sorted_paths = sorted(paths, reverse=True) # key=lambda x: len(x))
print('*****', sorted_paths[-1][-1])
return sorted_paths[-1][-1]
def path_to(self, v):
if not self.has_path_to(v):
return []
path = Stack()
x = v
while x != self.s:
path.push(x)
x = self.edge_to[x]
path.push(self.s)
return path
def dfs_recursive(self, starting_vertex: T,
destination_vertex: T) -> PathType:
"""
Return a list containing a path from
starting_vertex to destination_vertex in
depth-first order.
This should be done using recursion.
"""
# would hold the found path to destination_vertex
correct_path = []
# holds the visited vertices
visited = set()
# initialize the stack class
stack = Stack()
# push the starting_vertex as a list
stack.push([starting_vertex])
# the inner recursive function
def inner_dfs_recursive(starting_vertex, destination_vertex):
# pops off a path from the stack
path = stack.pop()
# picks the last vertex from the path
current_vert = path[-1]
# base case of current_vert is the destination_vertex
if current_vert == destination_vertex:
# assess the nonlocal correct_path
nonlocal correct_path
# point correct_path to the path
correct_path = path
# return from the recursive function
return
# for neighbors of current_vert
for vertex in self.vertices[current_vert]:
# if vertex has not been visited
if vertex not in visited:
# add it to visited visited
visited.add(vertex)
# create a copy of path
new_path = list(path)
# append the vert to the new path
new_path.append(vertex)
# push the new path onto the stack
stack.push(new_path)
# recursively call inner_dfs_recursive with vertex as the starting_vertex
inner_dfs_recursive(vertex, destination_vertex)
# call the recursive function
inner_dfs_recursive(starting_vertex, destination_vertex)
# return the path
return correct_path
def playing(player):
traversal_path = []
visited_dict = {}
visited_set = set()
path = Stack()
oposite_directions = {"s": "n", "n": "s", "e": "w", "w": "e"}
while len(visited_set) < len(room_graph):
current = player.current_room
visited_set.add(current)
# path.push(current.id)
# traversal_path.append(current)
# if current.id not in visited_set:
# print(current.id)
# visited_set.add(current.id)
visited_dict[current.id] = {}
# if len(current.get_exits()) == 1:
# direction = current.get_exits()
# path.pop()
# previous_room = path.stack[-1]
# visited_dict[current.id][direction] = previous_room
# player.travel(previous_room)
unvisited = Queue()
for direction in current.get_exits():
if current.get_room_in_direction(direction) not in visited_set:
# visited_dict[current.id][direction] = False
# unvisited.enqueue(direction)
unvisited.enqueue(direction)
if unvisited.size() > 0:
# direction = unvisited.dequeue()
direction = unvisited.dequeue()
path.push(direction)
traversal_path.append(direction)
player.travel(direction)
else:
# for direction in visited_dict[current.id]:
# if visited_dict[current.id][direction] == False:
# visited_dict[current.id][direction] = player.current_room.get_room_in_direction(direction)
# player.travel(direction)
previous_room = path.pop()
traversal_path.append(oposite_directions[previous_room])
player.travel(oposite_directions[previous_room])
return traversal_path
def evaluate(self, vars):
stack = Stack()
queue = Queue()
for elem in self._rpn:
factory = OperatorFactory()
operator = factory.newOperator(elem, stack, vars)
if self.verbose == True:
print elem, operator.evaluate()
stack.push(operator.evaluate())
if self.verbose == True:
print stack.s()
return stack.popAll()
def evaluate(self, vars):
stack = Stack()
queue = Queue()
for elem in self._rpn:
factory = OperatorFactory()
operator = factory.newOperator(elem, stack, vars)
if self.verbose == True:
print elem, operator.evaluate()
stack.push(operator.evaluate())
if self.verbose == True:
print stack.s()
return stack.popAll()
def sort_stack(stack):
s1 = stack
s2 = Stack(s1.size)
while(s1.is_empty() != True):
temp = s1.pop()
while(s2.is_empty() != True and s2.peek() > temp):
s1.push(s2.pop())
s2.push(temp)
return s2
def sort_stack(stack):
buf = Stack()
while not stack.is_empty():
cur = stack.pop()
cnt = 0
while not buf.is_empty() and cur < buf.peek():
stack.push(buf.pop())
cnt += 1
buf.push(cur)
for i in xrange(cnt):
buf.push(stack.pop())
while not buf.is_empty():
stack.push(buf.pop())
def push(self, value):
if self.cur_stack_index < 0:
self.stacks.append(Stack())
self.cur_stack_index = 0
cur_stack = self.stacks[self.cur_stack_index]
if cur_stack.size == self.threshold:
cur_stack = Stack()
self.stacks.append(cur_stack)
self.cur_stack_index += 1
cur_stack.push(value)
class MyQueue:
def __init__(self):
self.s1 = Stack()
self.s2 = Stack()
def enqueue(self, item):
self.s1.push(item)
def dequeue(self):
if self.s2.top is None:
while self.s1.top is not None:
self.s2.push(self.s1.pop())
return self.s2.pop()
def version_1(test):
forward_stack = Stack()
backward_stack = Stack()
for t in test:
forward_stack.push(t)
while not forward_stack.is_empty():
backward_stack.push(forward_stack.pop())
result = ''.join(backward_stack.to_array())
return test == result
def randomSteps(env, steps, dqn):
t0 = time.time()
env.reset()
i = 0
frame_stack = Stack(4)
initial_no_op = np.random.randint(4, NO_OP_MAX)
for _ in range(0, steps):
if i < initial_no_op:
# WE PERFORM A RANDOM NUMBER OF NO_OP ACTIONS
action = NO_OP_CODE
state, reward, done, info = env.step(action)
greyObservation = rgb2gray(state)
state = downSample(greyObservation)
frame_stack.push(state)
i += 1
else:
state = np.stack(frame_stack.items, axis=2).reshape(
(IMAGE_SIZE, IMAGE_SIZE, NUM_CHANNELS))
action = np.random.randint(0, len(ACTIONS))
actionH = np.zeros(len(ACTIONS))
actionH[action] = 1
next_state, reward, game_over, info = env.step(action)
greyObservation = rgb2gray(next_state)
next_state = downSample(greyObservation)
frame_stack.push(next_state)
next_state = np.stack(frame_stack.items, axis=2).reshape(
(IMAGE_SIZE, IMAGE_SIZE, NUM_CHANNELS))
dqn.storeExperience(state, actionH, reward, next_state, game_over)
if done:
#print("Episode finished after {} timesteps".format(_ + 1))
env.reset()
i = 0
frame_stack = []
t1 = time.time()
print(
"Fullfilling replay memory operation took:",
t1 - t0,
)
randomSteps()
class QueueViaStacks():
def __init__(self):
self.in_stack = Stack(5)
self.out_stack = Stack(5)
def enqueue(self, item):
self.in_stack.push(item)
def dequeue(self):
if self.out_stack.size == 0:
while self.in_stack.size:
self.out_stack.push(self.in_stack.pop())
if self.out_stack.is_empty is True:
raise IndexError("Can't dequeue from empty queue")
return self.out_stack.pop()
def get_convex_hull_by_graham_scan(angle_sorted_list):
temp_stack = Stack()
temp_stack.push(angle_sorted_list[0])
temp_stack.push(angle_sorted_list[1])
for p in angle_sorted_list[2:] + angle_sorted_list[:1]:
while True:
top = temp_stack.peek()
second_top = temp_stack.peek_peek()
b = (p[0] - top[0], p[1] - top[1])
a = (top[0] - second_top[0], top[1] - second_top[1])
if a[0] * b[1] - a[1] * b[0] < 0:
temp_stack.pop()
else:
break
temp_stack.push(p)
temp_stack.pop()
return temp_stack.items
class DepthFirstOrder:
def __init__(self, G):
self.marked = [False for _ in range(G.V)]
self.pre = Queue() # push v to queue before recursion
self.post = Queue() # ... after recursion
self.reverse_post = Stack() # push v to stack after recursion
for w in range(G.V):
if not self.marked[w]:
self.dfs(G, w)
def dfs(self, G, v):
self.pre.enqueue(v)
self.marked[v] = True
for w in G.adj[v]:
if not self.marked[w]:
self.dfs(G, w)
self.post.enqueue(v)
self.reverse_post.push(v)
def dft(self, starting_vertex):
"""
Print each vertex in depth-first order
beginning from starting_vertex.
"""
# make a stack
s = Stack()
# push on your starting node
s.push([starting_vertex])
# make a set to track if it was visited
visited = set()
# while stack not empty
while s.size() > 0:
# pop off what is on top.
current_node = s.pop()
# if we have no visited the vertex before
if current_node not in visited:
# run function/print
# print(current_node)
# mark as visited
# visited.add(current_node)
# get its neighbors
# neighbors = self.get_neighbors(current_node)
# for each of the neighbors
self.vertices[room.id] = {}
for neighbor in room.get_exits():
self.vertices[room.id][room.get_room_in_direction(
possible_direction).id] = neighbor
visited.add(room)
exits = room.get_exits()
while len(exits) > 0:
# select first neighbors on list
direct = exits[0]
# beej: create neighbor object
path = list(current_node)
# add possibles directions to move
path.append(room.get_room_in_direction(direct))
# add to stack
s.push(path)
# remove to contine
exits.remove(direct)
return self.vertices
class StackWithMin2(Stack):
def __init__(self):
super(StackWithMin2, self).__init__()
self.stack = Stack()
def pop(self):
item = super(StackWithMin2, self).pop()
if item == self.min():
self.stack.pop()
return item
def push(self, item):
if item <= self.min():
self.stack.push(item)
super(StackWithMin2, self).push(item)
def min(self):
if self.stack.top is not None:
return self.stack.top.val
else:
return 1e10
def parse_object(tokens):
s = Stack()
tokens_count = len(tokens)
n = 0
while n < tokens_count:
elem = tokens[n]
n += 1
if elem == ']':
l = []
while s.top() != '[':
top = s.pop()
l.insert(0, top)
s.pop()
s.push(l)
continue
if elem == '}':
l = []
while s.top() != '{':
top = s.pop()
l.insert(0, top)
s.pop()
if len(l) > 0 and not len(l) % 3 == 0 and not l.count(':') == len(l) / 3:
raise ValueError
d = {l[i]: l[i + 2] for i in range(0, len(l), 3)}
s.push(d)
continue
s.push(elem)
return s.top()
def evaluate(express):
ops = Stack()
vals = Stack()
for s in express.split():
if s in "+,-,*,/,sqrt".split(','):
ops.push(s)
elif s == '(':
pass
elif s == ')':
op = ops.pop()
v = vals.pop()
if op == '+':
v += vals.pop()
elif op == '-':
v -= vals.pop()
elif op == '*':
v *= vals.pop()
elif op == '/':
v /= vals.pop()
elif op == 'sqrt':
v = v**0.5
vals.push(v)
else:
vals.push(float(s))
return vals.pop()
def dfs(self, starting_vertex: T, destination_vertex: T) -> PathType:
"""
Return a list containing a path from
starting_vertex to destination_vertex in
depth-first order.
"""
# create the stack class
stack = Stack()
# would keep track of visited vertices
visited = set()
# push the starting vertex as a list of vert
stack.push([starting_vertex])
# while stack is not empty
while stack.size():
# pop a path from the stack
path = stack.pop()
# get the last vertex from the stack
current_vert = path[-1]
# if current_vert is the destination_vertex
if current_vert == destination_vertex:
# return path
return path
# if current_vert is not in visited:
if current_vert not in visited:
# add it to visited
visited.add(current_vert)
# for every neighbors of of current_vert
for vertex in self.vertices[current_vert]:
# create a copy of the path
new_path = list(path)
# append the current vertex
new_path.append(vertex)
# push the new path onto the stack
stack.push(new_path)
def depth_limited(problem, limit):
"""Depth Limited Search"""
frontier = Stack()
start_node = Node(problem['start'])
frontier.push(start_node)
closed_set = set()
while not frontier.isEmpty():
node = frontier.pop()
closed_set.add(node.value)
if goal_test(problem, node):
path = node.get_path()
cost = cal_path_cost(problem['graph'], path)
return path, cost, frontier.count
if node.depth == limit:
pass
else:
# Expansion
adj = problem['graph'].adj(node.value)
for child_value in quicksort(adj):
if push_or_not(problem, node, child_value, closed_set):
child_node = Node(child_value, node)
frontier.push(child_node)
return None
def dft(self, starting_vertex):
"""
Print each vertex in depth-first order
beginning from starting_vertex.
"""
# make a stack
stack = Stack()
# make a visited set
visited = set()
# put starting vertex in the stack
stack.push(starting_vertex)
# while the stack isn't empty
while stack.size():
# Pop off the top of the stack, it is current item
node = stack.pop()
# if node isn't visited
if node not in visited:
print(node)
# mark as visited
visited.add(node)
# for each of our current item's edges
for edge in self.vertices[node]:
stack.push(edge)
def dft(starting_position):
"""
Print each vertex in depth-first order
beginning from starting_vertex.
"""
# Create a queue/stack as appropriate
stack = Stack()
# Put the starting point in that
stack.push(starting_position.current_room)
# Make a set to keep track of where we've been
visited = {}
# While there is stuff in the queue/stack
while stack.size() > 0:
# Pop the first item
position = stack.pop()
# If not visited
if position.id not in visited:
# DO THE THING!
exits = position.get_exits()
visited[position.id] = {'n': '?', 's': '?', 'w': '?', 'e': '?'}
for exit in exits:
for idx, val in visited[position.id].items():
if idx == exit:
if idx == 'n':
visited[position.id][idx] = position.n_to.id
if idx == 's':
visited[position.id][idx] = position.s_to.id
if idx == 'e':
visited[position.id][idx] = position.e_to.id
if idx == 'w':
visited[position.id][idx] = position.w_to.id
for next_position in world.rooms:
stack.push(world.rooms[next_position])
return visited
class Program:
def __init__(self):
self.focus = Stack()
self.running = False
self.win = None
self.s = None
self.tabs = None
self.bomb = None
def init_state(self):
self.modules = [None, None, None, None, None, None, None, None]
self.tabs = Tabs(5, 0, *["Empty"] * 8)
self.focus = Stack()
self.slot = -1
bomb = self.bomb = Bomb(self)
bomb.notify_on_finish(self.bomb_info_finished)
self.update_bomb_info(bomb)
chooser = ModuleChooser(self)
self.focus.push(chooser)
self.focus.push(bomb)
def run(self, screen):
if self.running:
return
self.running = True
self.screen = screen
curses.noecho()
curses.curs_set(0)
curses.init_pair(1, curses.COLOR_RED, curses.COLOR_BLACK)
curses.init_pair(2, curses.COLOR_BLUE, curses.COLOR_BLACK)
curses.init_pair(3, curses.COLOR_BLACK, curses.COLOR_WHITE)
max_y, max_y = screen.getmaxyx()
self.win = win = curses.newwin(50, max_y, 7, 0)
win.keypad(1)
self.init_state()
self.add_decoration()
self.tabs.update(screen)
while True:
logging.debug("Program: Updating current object {:}".format(self.focus.cur()))
self.focus.cur().update(win)
logging.debug("Program: Refreshing window")
screen.refresh()
win.refresh()
logging.debug("Program: Waiting for event")
ev = win.getch()
if ev == curses.KEY_F12:
return
elif ev == curses.KEY_F10:
if not type(self.focus.cur()) is Bomb:
self.slot = -1
win.erase()
self.focus.push(self.bomb)
elif ev == curses.KEY_F11:
self.init_state()
elif curses.KEY_F1 <= ev <= curses.KEY_F8:
curses.curs_set(0)
self.slot = ev - curses.KEY_F1
logging.debug("Program: Selected module {}".format(self.slot))
if not type(self.focus.cur()) is ModuleChooser:
self.focus.pop()
if self.modules[self.slot]:
logging.debug("Program: Current module active: {!s:}".format(self.focus.cur()))
self.focus.push(self.modules[self.slot])
self.win.erase()
else:
self.focus.cur().event(ev, chr(ev))
self.tabs.set_active(self.slot)
self.tabs.update(screen)
if self.focus.cur() is None:
win.addstr(10, 50, "No module active")
def bomb_info_finished(self, bomb):
logging.debug("Program: Bomb info finished")
self.update_bomb_info(bomb)
if self.slot == -1:
self.slot = 0
self.focus.pop()
def update_bomb_info(self, bomb):
self.screen.move(1,0)
self.screen.clrtoeol()
self.screen.addstr("batteries: {!s: <9} parallel: {}".format(bomb.batteries, bomb.parallel))
self.screen.move(2,0)
self.screen.clrtoeol()
self.screen.addstr("serial: {!s: <9} vowels: {}".format(bomb.serial, bomb.vowels))
self.screen.move(3,0)
self.screen.clrtoeol()
self.screen.addstr("FRK: {!s: <9} CAR: {}".format(bomb.frk, bomb.car))
def set_module(self, module):
self.modules[self.slot] = module
self.tabs.set_tab(self.slot, module.title)
self.focus.push(module)
def add_decoration(self):
self.screen.addstr(0,0, " Keep talking and Nobody Explodes - Manual helper", curses.A_REVERSE | curses.A_BOLD)
y, x = self.screen.getyx()
max_y, max_x = self.screen.getmaxyx()
length = max_x - x
self.screen.addstr(" " * length, curses.A_REVERSE | curses.A_BOLD)
self.screen.addstr(6,0, "─" * max_x)
def convert(self, verbose):
self.verbose = verbose
operators = "^*+-\/"
# operands = string.ascii_lowercase + string.digits
output = Queue()
stack = Stack()
for token in self.infix:
operands = re.match("^[a-z]$|^\d+\.\d+$|^\d+$", token)
operators = re.match("^[+-\/*^]$", token)
# if token is a number or variable add it to putput
if operands:
output.push(token)
if self.verbose == True:
print "1 token = %s, output = %s" % (token, output.list[::-1])
# if the token is variable add it mapVariable dictionary
if token in string.ascii_lowercase:
self.mapVariables[token] = ""
# if token is an operator
elif operators:
# while there is another operator on the stack
while not stack.isEmpty():
# if operator is lef-associative and its precedence is less than or equal to that on stack, or operator has precedence less than that on stack (is not left-associative)
if stack.lastOnStack() != "(" and (
(
self.precedence[token][0] <= self.precedence[stack.lastOnStack()][0]
and self.precedence[token][1] == "L"
)
or self.precedence[token][0] < self.precedence[stack.lastOnStack()][0]
):
# push operator to output from stack
output.push(stack.pop())
if self.verbose == True:
print "2 token = %s, output = %s" % (token, output.list[::-1])
else:
break
# push operator to stack
stack.push(token)
if self.verbose == True:
print "3 token = %s, stack = %s" % (token, stack.list[::-1])
# if token is left parenthesis push it to stack
elif token == "(":
stack.push(token)
if self.verbose == True:
print "4 token = %s, stack = %s" % (token, stack.list[::-1])
# if token is right parenthesis
elif token == ")":
# until token at the top of stack is not left parethesis
while stack.lastOnStack() != "(":
# push from stack to output
output.push(stack.pop())
if self.verbose == True:
print "5 token = %s, output = %s" % (token, output.list[::-1])
# and pop left parethesis from stack but not to output
stack.pop()
if self.verbose == True:
print "Left on stack " + str(stack.list[::-1])
print "Output " + str(output.list)
self._rpn = output.list[::-1]
while len(stack.list) > 0:
self._rpn.append(stack.pop())
if self.verbose == True:
print "RPN value = " + str(self._rpn)
return self._rpn
class DbSession(object):
"""Provides an API for users to make changes to an in-memory database with transactions.
Attributes:
database: An instance of an in-memory database.
transaction_stack: A stack of active transactions.
current_trans: The currently active transaction. Transactions are a set of keys which
represent keys in the database that have been edited during the current transaction.
"""
def __init__(self):
self.database = InMemoryDatabase()
self.transaction_stack = Stack()
self.current_trans = None
self.reset_transaction_state()
def reset_transaction_state(self):
self.current_trans = set() if self.transaction_stack.is_empty() else self.transaction_stack.current()
# Transaction stack should always have a 'base' transaction which can't be rolled back/commited
self.transaction_stack = Stack(self.current_trans)
def pop_transaction(self):
self.transaction_stack.pop()
self.current_trans = self.transaction_stack.current()
def has_open_transaction(self):
return self.transaction_stack.size() > 1
def begin(self):
self.current_trans = set()
self.transaction_stack.push(self.current_trans)
def rollback(self):
if not self.has_open_transaction():
print('NO TRANSACTION')
else:
map(self.database.remove, list(self.current_trans))
self.pop_transaction()
def commit(self):
if not self.has_open_transaction():
print('NO TRANSACTION')
else:
self.database.flatten()
self.reset_transaction_state()
def set_var(self, var, value):
if var in self.current_trans:
self.database.change(var, value)
else:
self.database.add(var, value)
self.current_trans.add(var)
def unset_var(self, var):
self.set_var(var, None)
def get_var(self, var):
print(self.database.get(var) or 'NULL')
def num_equal_to(self, value):
print(self.database.num_equal_to(value))
def __repr__(self):
return '{}\nTransaction Stack: {}'.format(self.database, self.transaction_stack)
