python - Tkinter 回调中的异常：未定义名称“selected_book”

Question

我正在尝试构建一个简单的 GUI 应用程序，但出现一个错误，提示“未定义名称 'selected_book'”，但它是一个全局变量。我正在尝试将变量值传递给delete_book()函数，但此函数在另一个脚本中。有人请帮帮我。

这是我的第一个脚本：

from tkinter import *
from prog2 import *

window = Tk()

def get_selected_id(event) :
    global selected_book
    id = list1.curselection()[0]
    selected_book = list1.get(id)[0]

def view_all_cmd() :
    list1.delete(0, END)
    for row in view_all() :
        list1.insert(END, row)

def search_book_cmd() :
    list1.delete(0, END)
    for row in search_book(title_entry.get(), author_entry.get(), year_entry.get(), book_ID_entry.get()) :
        list1.insert(END, row)

def add_book_cmd() :
    list1.delete(0, END)
    add_book(title_entry.get(), author_entry.get(), year_entry.get(), id_entry.get())
    list1.insert(END, (title_entry.get(), author_entry.get(), year_entry.get(), bookID_entry.get()))

def delete_book_cmd() :
    view_all_cmd()
    delete_book(selected_book)

l1 = Label(window, text = "Title")
l1.grid(row = 0, column = 0)

l1 = Label(window, text = "Author")
l1.grid(row = 0, column = 2)

l1 = Label(window, text = "Year")
l1.grid(row = 1, column = 0)

l1 = Label(window, text = "Book ID")
l1.grid(row = 1, column = 2)

title_entry = StringVar()
e1 = Entry(window, textvariable = title_entry)
e1.grid(row = 0, column = 1)

author_entry = StringVar()
e2 = Entry(window, textvariable = author_entry)
e2.grid(row = 0, column = 3)

year_entry = StringVar()
e3 = Entry(window, textvariable = year_entry)
e3.grid(row = 1, column = 1)

bookID_entry = StringVar()
e4 = Entry(window, textvariable = bookID_entry)
e4.grid(row = 1, column = 3)

list1 = Listbox(window, height = 7, width = 35)
list1.grid(row = 2, column = 0,rowspan = 7, columnspan = 2)

sb1 = Scrollbar(window)
sb1.grid(row = 2 ,column = 2, rowspan = 6)

list1.configure(yscrollcommand = sb1.set)
sb1.configure(command = list1.yview)

list1.bind('<<ListboxSelect>>', get_selected_id)

b1 = Button(window, text = "View All", width = 15, command = view_all_cmd)
b1.grid(row = 2, column = 3)

b2 = Button(window, text = "Search Book", width = 15, command = search_book_cmd)
b2.grid(row = 3, column = 3)

b3 = Button(window, text = "Add Book", width = 15, command = add_book_cmd)
b3.grid(row = 4, column = 3)

b4 = Button(window, text = "Update Book", width = 15, command = update_book_cmd)
b4.grid(row = 5, column = 3)

b5 = Button(window, text = "Detele Book", width = 15, command = delete_book_cmd)
b5.grid(row = 6, column = 3)

b6 = Button(window, text = "Close", width = 15)
b6.grid(row = 7, column = 3)

window.mainloop()

这是我的第二个脚本：

import sqlite3

conn = sqlite3.connect("Books.db")
cur = conn.cursor()
cur.execute("CREATE TABLE IF NOT EXISTS books(id INTEGER PRIMARY KEY, title TEXT,author TEXT, year INTEGER, bookID INTEGER)")

def add_book(title, author, year, bookID) :
    conn = sqlite3.connect("Books.db")
    cur = conn.cursor()
    cur.execute("INSERT INTO books VALUES(NULL, ?, ?, ?, ?)", (title, author, year, bookID))
    conn.commit()
    conn.close()

def search_book(title = "", author = "", year = "", bookID = "") :
    conn = sqlite3.connect("Books.db")
    cur = conn.cursor()
    cur.execute("SELECT * FROM books WHERE title = ? OR author = ? OR year = ? OR bookID = ?", (title, author, year, bookID))
    data = cur.fetchall()
    conn.close()
    return data

def delete_book(id) :
    conn = sqlite3.connect("Books.db")
    cur = conn.cursor()
    cur.execute("DELETE FROM books WHERE id = ?", (id))
    conn.commit()
    conn.close()

def update_book(id, title, author, year, bookID) :
    conn = sqlite3.connect("Books.db")
    cur = conn.cursor()
    cur.execute("UPDATE books SET title = ?, author = ?, year = ?, bookID = ? WHERE id =?", (title, author, year, bookID, id))
    conn.commit()
    conn.close()

def view_all() :
    conn = sqlite3.connect("Books.db")
    cur = conn.cursor()
    cur.execute("SELECT * FROM books")
    data = cur.fetchall()
    conn.close()
    return data

这是我的错误：

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\ashak\AppData\Local\Programs\Python\Python38-32\lib\tkinter\__init__.py", line 1883, in __call__
    return self.func(*args)
  File ".\prog1.py", line 31, in delete_book_cmd
    delete_book(selected_book)
NameError: name 'selected_book' is not defined

有人能帮我吗？

标签： pythontkinter