What is wrong in my code?

Question

import random
import os

#draw grid

CELLS = [(0,0), (1,0), (2,0), (3,0), (4,0),
         (0,1), (1,1), (2,1), (3,1), (4,1),
         (0,2), (1,2), (2,2), (3,2), (4,2),
         (0,3), (1,3), (2,3), (3,3), (4,3),
         (0,4), (1,4), (2,4), (3,4), (4,4)]


def clear_screen():
  os.system('cls' if os.name == 'nt' else 'clear')


def get_location():
  return random.sample(CELLS, 3)


def move_player(player, move):
  x, y = player
  if move == 'LEFT':
    x -= 1
  if move == 'RIGHT':
    x += 1
  if move == 'UP':
    y -= 1
  if move == 'DOWN':
    y += 1
  return player


def get_moves(player):
  moves = ["LEFT", "RIGHT", "UP", "DOWN"]
  x, y = player
  if x == 0:
    moves.remove("LEFT")
  if x == 4:
    moves.remove("RIGHT")
  if y == 0:
    moves.remove("UP")
  if y == 4:
    moves.remove("DOWN")
  return x, y


monster, door, player = get_location()


while True:
  valid_moves = get_moves(player)
  clear_screen()
  print("Welcome to the dungeon!")
  print("You're currently in room {}".format(player))
  print("You can make the following moves {}".format(", ".join(valid_moves)))
  print("Enter QUIT to quit")


  move = input("> ")
  move = move.upper()


  if move == 'QUIT':
      break
  if move in valid_moves:
    player = move_player(player, move)
  else:
    print("\n ** Walls are Hard! Don't run into them **\n")
    continue

I have a mistake : Welcome to the dungeon!
You're currently in room (0, 1)
Traceback (most recent call last):
File "dungeon_game.py", line 56, in <module>
print("You can make the following moves {}".format(", ".join(valid_moves)))
TypeError: sequence item 0: expected str instance, int found

Answer 1 · 2017-02-26T06:52:52Z

February 26, 2017 6:52am

Hi, The error in your code is in the function get_moves(player), the function should return the list 'moves' instead you are returning a tuple of integers x,y. Thus the variable instead of containing list of moves instead contains a tuple of integers.

@Charles Kenney: python dynamically determines the type of variables, you cannot define an integer statically. The reason the error is coming is because valid_moves contains tuple of integer. Casting the variable to string won't work.

def get_moves(player):
  moves = ["LEFT", "RIGHT", "UP", "DOWN"]
  x, y = player
  if x == 0:
    moves.remove("LEFT")
  if x == 4:
    moves.remove("RIGHT")
  if y == 0:
    moves.remove("UP")
  if y == 4:
    moves.remove("DOWN")
  return move

Answer 2 · 2017-02-25T16:05:02Z

February 25, 2017 4:05pm

You got a type error because you used an integer 'valid_moves' in your string interpolation on line 56! You can simply force valid_moves as a string by doing the following...

print("You can make the following moves {}".format(", ".join(str(valid_moves))))

your program will then output:

Welcome to the dungeon!
You're currently in room (3, 1)
You can make the following moves (, 3, ,,  , 1, )
Enter QUIT to quit

Cheers, Charles

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Ilia Galperin

Ilia Galperin

What is wrong in my code?

2 Answers

Ullas Savkoor

Ullas Savkoor

Charles Kenney

Charles Kenney