turtle window appears blank

Question

This is my code. It is in Python 3.5.2, and uses tkinter and turtle.

When the button is pressed to show the location of the item, the turtle window is blank. If I move all of the code regarding turtle to after call mainloop on the tkinter window, the turtle window opens after the tkinter window is closed and works fine.

How can I fix my code so it appears when the button is pressed though.

---

import csv
import collections
from tkinter import *

def direction(n):
    import turtle
    wn = turtle.Screen() #sets up window
    turtle.bgpic("WilleysMap.gif") #loads picture of map
    m = turtle.Turtle() #creates arrow
    m.speed(100) #sets the speed
    m.penup() #lifts pen so no marks are made
    m.forward(160)
    m.right(90)
    m.forward(80)
    m.speed(1) #reduces speed so path can be seen
    if n == 1:#------------------------------------------------------------------NU 1
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.right(90)
        m.forward(300)
        m.left(90)
        m.forward(80)
        wn.mainloop()       
    elif n == 2: #---------------------------------------------------------------NU 2
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.right(90)
        m.forward(235)
        m.left(90)
        m.forward(80)
        wn.mainloop()       
    elif n == 3: #---------------------------------------------------------------NU 3
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.right(90)
        m.forward(180)
        m.left(90)
        m.forward(80)
        wn.mainloop()
    elif n == 4: #---------------------------------------------------------------NU 4
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.right(90)
        m.forward(300)
        m.right(90)
        m.forward(80)
        wn.mainloop()
    elif n == 5: #---------------------------------------------------------------NU 5
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.right(90)
        m.forward(200)
        m.right(90)
        m.forward(80)
        wn.mainloop()       
    elif n == 6: #---------------------------------------------------------------NU DECK
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.right(90)
        m.forward(60)
        m.left(90)
        m.forward(80)
        wn.mainloop()
    elif n == 7: #---------------------------------------------------------------PARKING LOT
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.left(90)
        m.forward(50)
        m.left(45)
        m.forward(140)
        m.left(45)
        m.forward(100)
        m.left(45)
        m.forward(180)
        wn.mainloop()
    elif n == 8: #---------------------------------------------------------------HUT AREA
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(80)
        m.right(90)
        m.forward(40)
        wn.mainloop()
    elif n == 9: #---------------------------------------------------------------SIDE STRUCTURE 1
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(20)
        m.right(90)
        m.forward(180)
        m.left(90)
        m.forward(30)
        m.right(90)
        m.forward(80)
        wn.mainloop()
    else: #----------------------------------------------------------------------SIDE STRUCTURE 2
        m.pencolor("red")
        m.pensize(15)
        m.pendown()
        m.forward(80)
        m.right(90)
        m.forward(60)
        wn.mainloop()


with open('code.csv') as f: #loads itemDict from the code.csv file
    reader1 = csv.reader(f)
    itemDict = dict(reader1)

with open('loc.csv') as f: #loads itemLoc from the loc.csv file
    reader2 = csv.reader(f)
    itemLoc = dict(reader2)
itemLoc['Emerald Green Arborvitae'] = itemLoc.pop('Emerald Green Arborvitae') #corrects error in translation

global find
def evaluate(event):
    if entry.get() in itemDict:
        res.configure(text = "UPC: " + str(entry.get()) + "\n The " + itemDict[entry.get()] + " can be found at: " + itemLoc[itemDict[entry.get()]], font = "Verdana 15 bold")
    else:
        res.configure(text = "UPC: " + str(entry.get()) + "\n The UPC you entered is not listed", font = "Verdana 15 bold")

def show():
    if itemLoc[itemDict[entry.get()]] == 'NU 1':
        direction(1)
    elif itemLoc[itemDict[entry.get()]] == 'NU 2':
        direction(2)
    elif itemLoc[itemDict[entry.get()]] == 'NU 3':
        direction(3)    
    elif itemLoc[itemDict[entry.get()]] == 'NU 4':
        direction(4)
    elif itemLoc[itemDict[entry.get()]] == 'NU 5':
        direction(5)
    elif itemLoc[itemDict[entry.get()]] == 'NU DECK':
        direction(6)    
    elif itemLoc[itemDict[entry.get()]] == 'PARKING LOT':
        direction(7)    
    elif itemLoc[itemDict[entry.get()]] == 'HUT AREA':
        direction(8)
    elif itemLoc[itemDict[entry.get()]] == 'SIDE STRUCTURE 1':
        direction(9)    
    else:
        direction(10)

w = Tk()

w.geometry("650x700")


Label(w, text="Type UPC into entry bar. To see a visual representation of the items location, press the 'Show' button.", font = "Verdana 10").pack(anchor=W)
Label(w, text="").pack()

Label(w, text="Please enter UPC of item", font = "Verdana 10").pack()
Label(w, text="you would like to locate", font = "Verdana 10").pack()
Label(w, text="and press 'Enter'", font = "Verdana 10").pack()
entry = Entry(w)
entry.focus_set()

entry.bind("<Return>", evaluate)
entry.pack()

Label(w, text="").pack()

Button(w, text ="Show", command=show).pack()

Label(w, text="").pack()

res = Label(w)
res.pack()

Label(w, text="Scroll down to see all listed UPCs", font = "Verdana 10").pack()

scrollbar = Scrollbar(w)
scrollbar.pack(side=RIGHT, fill=Y)
T = Text(w, height=15, width=75, bg = 'blue', fg = 'white')
T.pack()
quote = ''
with open('code.csv', newline='') as f:
    reader = csv.reader(f)
    for row in reader:
        quote += ("" + row[0] + ' '*(13-len(row[0])) + row[1] + '\n')
T.insert(END, quote)
scrollbar.config(command=T.yview)

w.mainloop()

EDIT The problem lies in the line

turtle.bgpic("WilleysMap.gif")

If I put a # in front of it, the code works fine and the turtle graphics just draw over a white screen instead of the map. Does anyone know how to fix this error?

BTW, the data im loading is just a two columed CSV file. Looks like: Arborvitate, ARB1 Golden Willow, GW34 etc etc

EDIT Here is the error I get

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\lucas\AppData\Local\Programs\Python\Python35-32\lib\tkinter\__init__.py", line 1550, in __call__
    return self.func(*args)
  File "x-wingide-python-shell://86210440/2", line 173, in show
  File "x-wingide-python-shell://86210440/2", line 29, in direction
  File "<string>", line 8, in bgpic
  File "C:\Users\lucas\AppData\Local\Programs\Python\Python35-32\lib\turtle.py", line 1482, in bgpic
    self._setbgpic(self._bgpic, self._bgpics[picname])
  File "C:\Users\lucas\AppData\Local\Programs\Python\Python35-32\lib\turtle.py", line 738, in _setbgpic
    self.cv.itemconfig(item, image=image)
  File "<string>", line 1, in itemconfig
  File "C:\Users\lucas\AppData\Local\Programs\Python\Python35-32\lib\tkinter\__init__.py", line 2418, in itemconfigure
    return self._configure(('itemconfigure', tagOrId), cnf, kw)
  File "C:\Users\lucas\AppData\Local\Programs\Python\Python35-32\lib\tkinter\__init__.py", line 1321, in _configure
    self.tk.call(_flatten((self._w, cmd)) + self._options(cnf))
_tkinter.TclError: image "pyimage2" doesn't exist

Answer 1

Finally I run your code.

You have error:

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1540, in __call__
    return self.func(*args)
  File "<pyshell#6>", line 141, in show
    direction(1)
  File "<pyshell#6>", line 27, in direction
    wn.mainloop()
AttributeError: '_Screen' object has no attribute 'mainloop'

You try do wn.mainloop() but wn doesn't have method mainloop() but turtle has - so you need turtle.mainloop()

BTW: you could make code shorter and put one turtle.mainloop() below all if/elif/else

But turtle in background uses tkinter to display window and tkinter should run only one mainloop() and you already have w.mainloop() so you don't need turtle.mainloop()

---

BTW: global find doesn't create global variable. All variables created outside functions are global - so you need only

 find = some_variable

global is used inside function to inform function to use external variable instead of creating local one.

---

EDIT: example with modifications.

Because I don't have your data so I create only one place with name "example".

I had to use RawTurtle with tk.Canvas and tk.Toplevel to have better control on window with turtle. But you can use canvas directly in main window (without `tk.Toplevel') and have only one window.

I use pack(pady=20) to make space between labels.

I use text to describe tracks.

 'NU 1': 'f20 r90 f180 r90 f300 l90 f80',

Code:

import tkinter as tk
from  tkinter import messagebox
import turtle

def draw_track(track):
    win = tk.Toplevel()
    canvas = tk.Canvas(win, width=500, height=500)
    canvas.pack()
    m = turtle.RawTurtle(canvas)

    # move to start
    m.speed(100)
    m.penup()
    m.forward(160)
    m.right(90)
    m.forward(80)
    m.speed(1)

    # draw
    m.pencolor("red")
    m.pensize(15)
    m.pendown()

    # split text into command
    track = track.split()

    # execute commands
    for element in track:
        cmd = element[0]
        number = int(element[1:])
        if cmd == 'f':
            m.forward(number)
        elif cmd == 'r':
            m.right(number)
        elif cmd == 'l':
            m.left(number)

def evaluate(event):
    if entry.get() in itemDict:        
        text="UPC: {}\nThe {} can be found at: {}".format(entry.get(), itemDict[entry.get()], itemLoc[itemDict[entry.get()]])
    else:
        text="UPC: {}\nThe UPC you entered is not listed".format(entry.get())
    res.configure(text=text, font="Verdana 15 bold")

def show():
    text = entry.get().strip()
    if text in item_dict:
        track = data[item_loc[item_dict[text]]]
        draw_track(track)
    else:
        messagebox.showwarning("Warning", "No '{}' in dictionary".format(text))

# --- main ---

# - data -

item_dict = {'example': 1}
item_loc  = {1: 'NU 1'}

data = {
    'NU 1': 'f20 r90 f180 r90 f300 l90 f80',
    'NU 2': 'f20 r90 f180 r90 f235 l90 f80',
    'NU 3': 'f20 r90 f180 r90 f180 l90 f80',
    'NU 4': 'f20 r90 f180 r90 f300 r90 f80',
    'NU 5': 'f20 r90 f180 r90 f200 r90 f80',
    'NU DECK': 'f20 r90 f180 r90 f60 l90 f80',
    'PARKING LOT': 'f20 l90 f50 l45 f140 l45 f100 l45 f180',
    'HUT AREA': 'f20 r90 f80 r90 f40',
    'SIDE STRUCTURE 1': 'f20 r90 f180 l90 f30 r90 f80',
    'SIDE STRUCTURE 2': 'f80 r90 f60',
}

# - gui -

root = tk.Tk()

font = "Verdana 10"

l = tk.Label(root, text="Type UPC into entry bar.\nTo see a visual representation of the items location, press the 'Show' button.", font=font)
l.pack()

l = tk.Label(root, text="Please enter UPC of item\nyou would like to locate\nand press 'Enter'", font=font)
l.pack(pady=20)

entry = tk.Entry(root)
entry.pack()

entry.bind("<Return>", evaluate)
entry.focus_set()

b = tk.Button(root, text="Show", command=show)
b.pack(pady=20)

root.mainloop()