Замена ошибок с помощью настраиваемых сообщений

Question

Моя программа посвящена обработке изображений, и она запрашивает у пользователя при запуске, чтобы открыть изображение. Но если пользователь закрывает окно без выбора изображения, я получаю следующее сообщение об ошибке:

Traceback (most recent call last): 
    File "<string>", line 420, in run_nodebug 
    File "E:\Projet Complet\Test 2.py", line 255, in <module> 
    Ima1=Image.open(a) 
    File "C:\EduPython\App\lib\site-packages\PIL\Image.py", line 2317, in open 
    fp = io.BytesIO(fp.read()) 
AttributeError: 'str' object has no attribute 'read' 

Я пытаюсь заменить эту ошибку с помощью пользовательского сообщения, как "You didn't choose any image" в открытом окне сообщения. Я знаю, как открыть окно сообщения, но я не знаю, как заменить сообщение об ошибке. Я попытался сделать это:

main.withdraw() 
try: 
    a = filedialog.askopenfilename() 
    main.deiconify() 
except AttributeError: 
    tkMessageBox.showinfo("Image Error", "You didn't choose any image.") 
    sys.exit() 

Но это дает мне вышеуказанную ошибку. Вот полный код:

from tkinter import* 
import tkinter as Tkinter 
from tkinter import filedialog, DISABLED, messagebox as tkMessageBox 
import os 
import ntpath 
from PIL import Image, ImageTk, ImageFilter 
import PIL 
from collections import Counter 
from random import randint 
import random 
import PIL.ImageOps 


def EchelleDeGris(): 
    Ima2=Image.new("RGB",(z[0],z[1])) 
    px=Ima1.load() 
    px1=Ima2.load() 
    for x in range(z[0]): 
     for y in range(z[1]): 
      p=px[x,y] 
      if type(p)==int: 
       p=(p,p,p) 
      o=int((p[0]+p[1]+p[2])/3) 
      px1[x,y]=(o,o,o) 
    Ima2.save(""+dir_path+"\\Requirements\\ImageMod.png") 
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png") 
    main.image = im2 
    I2 = Tkinter.Label(main, image=im2) 
    I2.grid(row=0, column=4, columnspan =4) 

def SupprimerImage(): 
    I2 = Tkinter.Label(main, image=imt) 
    I2.grid(row=0, column=4, columnspan =4) 

def Luminosite(): 
    Ima2=Image.new("RGB",(z[0],z[1])) 
    px=Ima1.load() 
    px1=Ima2.load() 
    for x in range(z[0]): 
     for y in range(z[1]): 
      p=px[x,y] 
      if type(p)==int: 
       p=(p,p,p) 
      px1[x,y]=(p[0]+S1.get(),p[1]+S1.get(),p[2]+S1.get()) 
    Ima2.save(""+dir_path+"\\Requirements\\ImageMod.png") 
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png") 
    main.image = im2 
    I2 = Tkinter.Label(main, image=im2) 
    I2.grid(row=0, column=4, columnspan =4) 

def AnnulerModifications(): 
    I2 = Tkinter.Label(main, image=im1) 
    I2.grid(row=0, column=4, columnspan =4) 

def get_pixel(pixels, x, y): 
    try: 
     return pixels[x, y] 
    except IndexError: 
     return None 


def get_neighbors(pixels, x, y): 
    neighbors = list() 
    neighbors.append(get_pixel(pixels, x, y - 1)) 
    neighbors.append(get_pixel(pixels, x, y + 1)) 
    neighbors.append(get_pixel(pixels, x - 1, y)) 
    neighbors.append(get_pixel(pixels, x + 1, y)) 
    neighbors.append(get_pixel(pixels, x - 1, y - 1)) 
    neighbors.append(get_pixel(pixels, x - 1, y + 1)) 
    neighbors.append(get_pixel(pixels, x + 1, y - 1)) 
    neighbors.append(get_pixel(pixels, x + 1, y + 1)) 
    return neighbors 


def filter_art(pixels, size): 
    indexes = dict() 
    for x in range(size[0]): 
     for y in range(size[1]): 
      color = get_pixel(pixels, x, y) 
      neighbors = get_neighbors(pixels, x, y) 
      new_color = Counter(neighbors).most_common()[0][0] 
      if new_color is not None: 
       indexes[x, y] = new_color 
    for x, y in indexes: 
     pixels[x, y] = indexes[x, y] 


def pop_art(path_orig, path_mod, coef): 

    s=[] 
    for i in range(9): 

     r=(randint(0,255), randint(0,255), randint(0,255)) 
     g=(randint(0,255), randint(0,255), randint(0,255)) 
     b=(randint(0,255), randint(0,255), randint(0,255)) 

     image_orig = Image.open(path_orig) 
     size = image_orig.size 
     image_mod = Image.new("RGB",(size[0],size[1])) 
     pixels_orig = image_orig.load() 
     pixels_mod = image_mod.load() 
     for x in range(size[0]): 
      for y in range(size[1]): 
       p = pixels_orig[x, y] 
       if isinstance(p, int): 
        rgb = (p,p,p) 
       elif isinstance(p, tuple) and len(p) in (3, 4): 
        rgb = p[:3] 
       else: 
        raise TypeError('Unknown pallete') 
       average_color = sum(rgb)/3 
       if average_color <= 85: 
        pixels_mod[x, y] = r 
       elif 85 < average_color <= 170: 
        pixels_mod[x, y] = g 
       elif average_color > 170: 
        pixels_mod[x, y] = b 
     for _ in range(coef): 
      filter_art(pixels_mod, size) 
     image_mod.save(''+dir_path+'\\PopArt\\Modified Images\\result'+str(i)+'.png') 
     Img=[None]*9 
    for i in range(9): 
     Img[i]=Image.open(""+dir_path+"\\PopArt\\Modified Images\\result"+str(i)+".png") 
     basewidth = int(Img[i].size[1]/3) 
     wpercent = (basewidth/float(Img[i].size[0])) 
     hsize = int((float(Img[i].size[1]) * float(wpercent))) 
     Img[i] = Img[i].resize((basewidth , hsize), PIL.Image.ANTIALIAS) 
     Img[i].save(''+dir_path+'\\PopArt\\Resized Images\\resized_image'+str(i)+'.png') 


    Img1=[None]*9 
    pixels1=[None]*9 
    Imaz=Image.new("RGB",(basewidth*3,hsize*3)) 
    pixels=Imaz.load() 
    for i in range(9): 
     Img1[i]=Image.open(''+dir_path+'\\PopArt\\Resized Images\\resized_image'+str(i)+'.png') 
     pixels1[i]=Img1[i].load() 


    for x in range(0,basewidth): 
     for y in range(0,hsize): 
      pixels[x,y]=pixels1[0][x,y] 
     for y in range(hsize,hsize*2): 
      pixels[x,y]=pixels1[1][x,y-hsize] 
     for y in range(hsize*2,hsize*3): 
      pixels[x,y]=pixels1[2][x,y-hsize*2] 

    for x in range(basewidth,basewidth*2): 
     for y in range(0,hsize): 
      pixels[x,y]=pixels1[3][x-basewidth,y] 
     for y in range(hsize,hsize*2): 
      pixels[x,y]=pixels1[4][x-basewidth,y-hsize] 
     for y in range(hsize*2,hsize*3): 
      pixels[x,y]=pixels1[5][x-basewidth,y-hsize*2] 

    for x in range(basewidth*2,basewidth*3): 
     for y in range(0,hsize): 
      pixels[x,y]=pixels1[6][x-basewidth*2,y] 
     for y in range(hsize,hsize*2): 
      pixels[x,y]=pixels1[7][x-basewidth*2,y-hsize] 
     for y in range(hsize*2,hsize*3): 
      pixels[x,y]=pixels1[8][x-basewidth*2,y-hsize*2] 
    Imaz = Imaz.resize((size[0] , size[1]), PIL.Image.ANTIALIAS) 
    Imaz.save(""+dir_path+"\\PopArt\\Result Image\\result.png") 


def usepop(): 
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\traitement.png") 
    main.image = im2 
    I2 = Tkinter.Label(main, image=im2) 
    I2.grid(row=0, column=4, columnspan =4) 
    I2.update_idletasks() 
    pop_art(a, None, coef=4) 
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\PopArt\\Result Image\\result.png") 
    main.image = im2 
    I2 = Tkinter.Label(main, image=im2) 
    I2.grid(row=0, column=4, columnspan =4) 

def change_contrast(level): 

    img = Image.open(a) 
    img.load() 

    factor = (259 * (level+255))/(255 * (259-level)) 
    for x in range(img.size[0]): 
     for y in range(img.size[1]): 
      color = img.getpixel((x, y)) 
      if type(color) == int: 
       color=(color,color,color) 
       new_color = tuple(int(factor * (c-128) + 128) for c in color) 
       new_color = new_color[0] 
       img.putpixel((x, y), new_color) 
      elif type(color) != int: 
       new_color = tuple(int(factor * (c-128) + 128) for c in color) 
       img.putpixel((x, y), new_color) 
    return img 

def use_contrast(): 
    result = change_contrast(S2.get()) 
    result.save(""+dir_path+"\\Requirements\\ImageMod.png") 
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png") 
    main.image = im2 
    I2 = Tkinter.Label(main, image=im2) 
    I2.grid(row=0, column=4, columnspan =4) 

def recherche_contours(): 
    Ima2=Image.new("RGB",(z[0],z[1])) 
    px=Ima1.load() 
    px1=Ima2.load() 
    for x in range(z[0]): 
     for y in range(z[1]): 
      p=px[x,y] 
      if type(p)==int: 
       p=(p,p,p) 
      o=int((p[0]+p[1]+p[2])/3) 
      px1[x,y]=(o,o,o) 
    Ima2 = Ima2.filter(ImageFilter.FIND_EDGES) 
    image = Ima2 
    if image.mode == 'RGBA': 
     r,g,b,a = image.split() 
     rgb_image = Image.merge('RGB', (r,g,b)) 

     inverted_image = PIL.ImageOps.invert(rgb_image) 

     r2,g2,b2 = inverted_image.split() 

     final_transparent_image = Image.merge('RGBA', (r2,g2,b2,a)) 

     final_transparent_image.save(""+dir_path+"\\Requirements\\ImageMod.png") 

    else: 
     inverted_image = PIL.ImageOps.invert(image) 
     inverted_image.save(""+dir_path+"\\Requirements\\ImageMod.png") 
    im2 = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\ImageMod.png") 
    main.image = im2 
    I2 = Tkinter.Label(main, image=im2) 
    I2.grid(row=0, column=4, columnspan =4) 

main=Tk() 

main.withdraw() 
try: 
    a = filedialog.askopenfilename() 
    main.deiconify() 
except AttributeError: 
    tkMessageBox.showinfo("Resolution Error", "The image is too big, please select a smaller one.") 
    sys.exit() 


dir_path = os.path.dirname(os.path.realpath("Test2.py")) 

main.configure(background="#a1dbcd") 
main.title("Photoshop Version.Megzari") 
try: 
    Ima1=Image.open(a) 
    z=Ima1.size 
    nux=Image.new("RGB",(z[0],z[1])) 
    nuxy=nux.load() 
    for x in range(z[0]): 
     for y in range(z[1]): 
      nuxy[x,y]=(255,255,255) 
    nux.save(""+dir_path+"\\Requirements\\Blank.png") 


    main.withdraw() 
    a = filedialog.askopenfilename() 
except AttributeError: 
    tkMessageBox.showinfo("Image Error", "You didn't choose any image.") 
    sys.exit() 
main.deiconify() 

if z>(400,400): 
    main.withdraw() 
    tkMessageBox.showinfo("Resolution Error", "The image is too big, please select a smaller one.") 
    sys.exit() 

elif z<(400,400): 
    im1 = ImageTk.PhotoImage(file=a) 
    I1 = Tkinter.Label(main, image=im1) 
    I1.grid(row=0, column=1, columnspan =3) 
    imt = ImageTk.PhotoImage(file=""+dir_path+"\\Requirements\\Blank.png") 
    T1 = Tkinter.Label(main, image=imt) 
    T1.grid(row=0, column=4, columnspan =4) 
    B1 = Tkinter.Button(main, text ="Echelle de gris", command = EchelleDeGris, fg="#a1dbcd", bg="#383a39", state=NORMAL) 
    B1.grid(padx=20, pady=20, row=1, column=0) 
    B3 = Tkinter.Button(main, text ="Appliquer Luminosité", command = Luminosite, fg="#a1dbcd", bg="#383a39") 
    B3.grid(padx=20, pady=20, row=1, column=1) 
    S1 = Scale(main, from_=0, to=254, orient=HORIZONTAL, fg="#a1dbcd", bg="#383a39", length = 200) 
    S1.grid(row=2, column=1) 
    B2 = Tkinter.Button(main, text ="Supprimer Image", command = SupprimerImage, fg="#a1dbcd", bg="#383a39") 
    B2.grid(padx=20, pady=20, row=1, column=7) 
    B3 = Tkinter.Button(main, text ="Annuler Modifications", command = AnnulerModifications, fg="#a1dbcd", bg="#383a39") 
    B3.grid(padx=20, pady=20, row=1, column=6) 
    B4 = Tkinter.Button(main, text ="Pop Art", command = usepop, fg="#a1dbcd", bg="#383a39") 
    B4.grid(padx=20, pady=20, row=1, column=3) 
    S2 = Scale(main, from_=-258, to=258, orient=HORIZONTAL, fg="#a1dbcd", bg="#383a39", length = 200) 
    S2.grid(row=2, column=4) 
    B4 = Tkinter.Button(main, text ="Appliquer Contraste", command = use_contrast, fg="#a1dbcd", bg="#383a39") 
    B4.grid(padx=20, pady=20, row=1, column=4) 
    B5 = Tkinter.Button(main, text ="Trouver Contours", command = recherche_contours, fg="#a1dbcd", bg="#383a39") 
    B5.grid(padx=20, pady=20, row=1, column=5) 

    s=S1.get() 
    s2=S2.get() 




main.mainloop() 

EDIT1: Я применил ответ от @Juan T, и это было выведено сообщение, но не закрывает окно, даже если я инициированного sys.exit()

EDIT2: Я нашел, как это исправить все, что я должен был сделать, это добавить main.destroy() до того sys.exit()

EDIT3: Теперь, когда я запускаю код, я SELE ct изображение, и оно снова подсказывает мне изображение. Я хочу, чтобы он подсказывал это один раз.

EDIT4: Я исправил это, проблема была в том, что у меня был старый фрагмент, скрытый в коде, который вызывал проблему, теперь все в порядке.

Answer 1

Он работает, если вы положили try. Таким образом, вместо того, чтобы:

Ima1=Image.open(a) 
z=Ima1.size 
... 
nux.save(""+dir_path+"\\Requirements\\Blank.png") 


main.withdraw() 
try: 
    a = filedialog.askopenfilename() 
except AttributeError: 
    tkMessageBox.showinfo("Image Error", "You didn't choose any image.") 
    sys.exit() 
main.deiconify() 

Рассмотрим:

try: 
    Ima1=Image.open(a) 
    z=Ima1.size 
    ... 
    nux.save(""+dir_path+"\\Requirements\\Blank.png") 

    main.withdraw() 

    a = filedialog.askopenfilename() 
except AttributeError: 
    tkMessageBox.showinfo("Image Error", "You didn't choose any image.") 
    sys.exit() 
main.deiconify()