如何在python tkinter mainloop中定義一個列表而不改變它的值

Question

我試圖制作一個 python 程序來使用PyPDF2分割 pdf。 所以我必須定義一個列表來附加元素，但是當循環再次迭代時，列表的值會更改為空白列表。 因此，該程序將制作一個沒有任何內容的 pdf。 這是我的代碼

import tkinter as tk
from PIL import Image, ImageTk
from PyPDF2 import PdfFileReader, PdfFileWriter
from tkinter import filedialog
from tkinter import messagebox
  
elements = []
root7 = tk.Tk()
root7.geometry("600x600")
root7.title("PDF Viewer")
root7.configure(bg="#202020")

    
image7 = Image.open("split.jpg")
new_img7 = image7.resize((600,400))
photo7 = ImageTk.PhotoImage(new_img7)


def open1():
    pdf = filedialog.askopenfilename(initialdir = "/",title = "Select file",filetypes = (("pdf files","*.pdf"),("all files","*.*")))
    elements.append(pdf)

    w = tk.Spinbox(root7, from_=0, to=100, width=3)
    w.place(x=150, y=510)
    elements.append(int(w.get()))

    w1 = tk.Spinbox(root7, from_=0, to=100, width=3)
    w1.place(x=409, y=510)
    elements.append(int(w1.get()))
    
def split():
    pdfs = PdfFileReader(elements[0], "rb")
    pdf_writer = PdfFileWriter()

    for page in range(elements[1], elements[2]):
        pdf_writer.addPage(pdfs.getPage(page))

    output_fname = "splitted.pdf"

    with open(output_fname, 'wb') as out:
        pdf_writer.write(out)

    messagebox.showinfo("Splitted","PDF Saved in Desktop as splitted.pdf")
    

lbl7 = tk.Label(root7,image=photo7)
lbl7.place(x=0, y=0)

button7 = tk.Button(root7, text= 'Open PDF', command=open1, bg="#B8B8B8")
button7.place(width=300, height=50, x=150, y=450)

button8 = tk.Button(root7, text= 'Split PDF', command=split, bg="#B8B8B8")
button8.place(width=300, height=50, x=150, y=540)


root7.update()
root7.mainloop()

有人請幫忙。

Answer 1

我終於找到了答案。 問題不在於列表，而是在我取 spinbox 小部件的初始值時引起的，這里是修改后的代碼。

import tkinter as tk
from PIL import Image, ImageTk
from PyPDF2 import PdfFileReader, PdfFileWriter
from tkinter import filedialog
from tkinter import messagebox
  
w = 0
w1 = 0
root7 = tk.Toplevel()
root7.geometry("600x600")
root7.title("PDF Splitter")
root7.configure(bg="#202020")
elements = []

    
image7 = Image.open("split.jpg")
new_img7 = image7.resize((600,400))
photo7 = ImageTk.PhotoImage(new_img7)


def open1():
    global w, w1
    pdf = filedialog.askopenfilename(initialdir = "/",title = "Select file",filetypes = (("pdf files","*.pdf"),("all files","*.*")))
    elements.append(pdf)

    w = tk.Spinbox(root7, from_=0, to=100, width=3)
    w.place(x=150, y=510)
    

    w1 = tk.Spinbox(root7, from_=0, to=100, width=3)
    w1.place(x=409, y=510)
    elements.append(int(w1.get()))
    
def split():
    global w, w1
    pdfs = PdfFileReader(elements[0], "rb")
    pdf_writer = PdfFileWriter()

    elements.append(int(w.get()))
    elements.append(int(w1.get()))

    w2 = int(w.get())
    w3 = int(w1.get())

    for page in range(45):
        pdf_writer.addPage(pdfs.getPage(w2-1))
        w2+=1
        if (w2-1)==(w3):
            break

    output_fname = "splitted.pdf"

    with open(output_fname, 'wb') as out:
        pdf_writer.write(out)

    messagebox.showinfo("Splitted","PDF Saved in Desktop as splitted.pdf")
    

lbl7 = tk.Label(root7,image=photo7)
lbl7.place(x=0, y=0)

button7 = tk.Button(root7, text= 'Open PDF', command=open1, bg="#B8B8B8")
button7.place(width=300, height=50, x=150, y=450)

button8 = tk.Button(root7, text= 'Split PDF', command=split, bg="#B8B8B8")
button8.place(width=300, height=50, x=150, y=540)


root7.update()
root7.mainloop()

GUI 不好，但它仍然有效。