python错误从cmd运行

Question

对于我的课程作业，我正在做一个使用一些树视图的预订系统。问题是，如果当我双击树视图中的一行时从 cmd 运行它不会填充它下面的框，但是如果我从空闲运行它它会。下面是我创建课程的地方和两个定义，它们是 create_GUI（用于双击前 gui 的第一部分）和双击（创建 GUI 的第二部分）

from tkinter import *
import os
import datetime
import sqlite3
from tkinter.ttk import Combobox,Treeview,Scrollbar
import tkinter as tk
import Utilities


class Application(Frame):
    """ Binary to Decimal """ 
    def __init__(self, master):
        """ Initialize the frame. """
        super(Application, self).__init__(master)
        self.grid()
        self.create_GUI()

    def Quit(self):
        self.master.destroy()

    def create_GUI(self):
        frame1 = tk.LabelFrame(root, text="frame1", width=300, height=130, bd=5)
        frame2 = tk.LabelFrame(root, text="frame2", width=300, height=130, bd=5)
        frame1.grid(row=0, column=0, columnspan=3, padx=8)
        frame2.grid(row=1, column=0, columnspan=3, padx=8)
        self.title_lbl = Label(frame1, text = "Students")
        self.title_lbl.grid(row = 0, column = 2)

        self.fn_lbl = Label(frame1, text = "First Name:")
        self.fn_lbl.grid(row = 1 , column = 1)

        self.fn_txt = Entry(frame1)
        self.fn_txt.grid(row = 1, column = 2)

        self.ln_lbl =Label(frame1, text = "Last Name:")
        self.ln_lbl.grid(row = 2, column = 1)

        self.ln_txt = Entry(frame1)
        self.ln_txt.grid(row = 2, column = 2)

        self.q_btn = Button(frame1, text = "Back",padx=80,pady=10, command = lambda: self.Quit())
        self.q_btn.grid(row = 3, column = 0)

        self.s_btn = Button(frame1, text = "search",padx=80,pady=10, command = lambda: self.search())
        self.s_btn.grid(row = 3,column = 3)

        self.tree = Treeview(frame2,height = 6)
        self.tree["columns"] = ("StudentID","First Name","Last Name")#,"House Number", "Street Name", "Town Or City Name","PostCode","MobilePhoneNumber")
        self.tree.column("StudentID",width = 100)
        self.tree.column("First Name",width = 100)
        self.tree.column("Last Name", width = 100)
##        self.tree.column("House Number", width = 60)
##        self.tree.column("Street Name", width = 60)
##        self.tree.column("Town Or City Name", width = 60)
##        self.tree.column("PostCode", width = 60)
##        self.tree.column("MobilePhoneNumber", width = 60)

        self.tree.heading("StudentID",text="StudentID")
        self.tree.heading("First Name",text="First Name")
        self.tree.heading("Last Name",text="Last Name")
##        self.tree.heading("House Number",text="House Number")
##        self.tree.heading("Street Name",text="Street Name")
##        self.tree.heading("Town Or City Name",text="Town Or City Name")
##        self.tree.heading("PostCode",text="PostCode")
##        self.tree.heading("MobilePhoneNumber",text="MobilePhoneNumber")

        self.tree["show"] = "headings"
        yscrollbar = Scrollbar(frame2, orient='vertical', command=self.tree.yview)
        xscrollbar = Scrollbar(frame2, orient='horizontal', command=self.tree.xview)
        self.tree.configure(yscroll=yscrollbar.set, xscroll=xscrollbar.set)
        yscrollbar.grid(row=1, column=5, padx=2, pady=2, sticky=NS)
        self.tree.grid(row=1,column=0,columnspan =5, padx=2,pady=2,sticky =NSEW)
        self.tree.bind("<Double-1>",lambda event :self.OnDoubleClick(event))

    def OnDoubleClick(self, event):
        frame3 = tk.LabelFrame(root, text="frame1", width=300, height=130, bd=5)
        frame3.grid(row=2, column=0, columnspan=3, padx=8)
        self.message=StringVar()
        self.message.set("")
        self.lblupdate = Label(frame3, textvariable = self.message).grid(row=0,column=0,sticky=W)
        curItem = self.tree.focus()
        contents =(self.tree.item(curItem))
        StudentDetails = contents['values']
        print(StudentDetails)

        self.tStudentID=StringVar()
        self.tFirstName = StringVar()
        self.tLastName = StringVar()
        self.tHouseNumber = StringVar()
        self.tStreetName = StringVar()
        self.tTownOrCityName = StringVar()
        self.tPostCode = StringVar()
        self.tEmail = StringVar()
        self.tMobilePhoneNumber = StringVar()

        self.tStudentID.set(StudentDetails[0])
        self.tFirstName.set(StudentDetails[1])
        self.tLastName.set(StudentDetails[2])
        self.tHouseNumber.set(StudentDetails[3])
        self.tStreetName.set(StudentDetails[4])
        self.tTownOrCityName.set(StudentDetails[5])
        self.tPostCode.set(StudentDetails[6])
        self.tEmail.set(StudentDetails[7])
        self.tMobilePhoneNumber.set(StudentDetails[8])

        self.inst_lbl0 = Label(frame3, text = "Student ID").grid(row=5,column=0,sticky=W)
        self.StudentID = Label(frame3, textvariable=self.tStudentID).grid(row =5,column=1,stick=W)
        self.inst_lbl1 = Label(frame3, text = "First Name").grid(row=6,column=0,sticky=W)
        self.NFirstName = Entry(frame3, textvariable=self.tFirstName).grid(row =6,column=1,stick=W)
        self.inst_lbl2 = Label(frame3, text = "Last Name").grid(row=7,column=0,sticky=W)
        self.NLastName = Entry(frame3, textvariable=self.tLastName).grid(row =7,column=1,stick=W)
        self.inst_lbl3 = Label(frame3, text = "House Number").grid(row=8,column=0,sticky=W)
        self.HouseNumber = Entry(frame3,textvariable=self.tHouseNumber).grid(row=8,column=1,sticky=W)
        self.inst_lbl4 = Label(frame3, text = "Street Name").grid(row=9,column=0,sticky=W)
        self.StreetName =Entry(frame3,textvariable=self.tStreetName).grid(row=9,column=1,sticky=W)
        self.inst_lbl5 = Label(frame3, text = "Town or City Name").grid(row=10,column=0,sticky=W)
        self.TownOrCityName =Entry(frame3,textvariable=self.tTownOrCityName).grid(row=10,column=1,sticky=W)
        self.inst_lbl6 = Label(frame3, text = "Postcode").grid(row=11,column=0,sticky=W)
        self.PostCode = Entry(frame3,textvariable=self.tPostCode).grid(row=11,column=1,sticky=W)
        self.inst_lbl7 = Label(frame3, text = "Email").grid(row=12,column=0,sticky=W)
        self.Email =Entry(frame3,textvariable=self.tEmail).grid(row=12,column=1,sticky=W)
        self.inst_lbl8 = Label(frame3, text = "Mobile phonenumber").grid(row=13,column=0,sticky=W)
        self.MobilePhoneNumber =Entry(frame3,textvariable=self.tMobilePhoneNumber).grid(row=13,column=1,sticky=W)

        self.btnSaveChanges = Button(frame3, text = "save changes",padx=80,pady=10,command = lambda:self.SaveChanges()).grid(row=14,column=0,sticky=W)
        self.btnSaveChanges = Button(frame3, text = "delete record",padx=80,pady=10,command = lambda:self.DeleteRecord()).grid(row=14,column=1,sticky=W)


    def search(self):
        FirstName = self.fn_txt.get()
        LastName = self.ln_txt.get()
        with sqlite3.connect("GuitarLessons.db") as db:
            cursor = db.cursor()
            cursor.row_factory = sqlite3.Row
            sql = "select StudentID,FirstName,LastName,HouseNumber,StreetName,TownOrCityName,PostCode,Email,MobilePhoneNumber"\
                  " from tblStudents"\
                  " where FirstName like ?"\
                  " and LastName like ?"
            cursor.execute(sql,("%"+FirstName+"%","%"+LastName+"%",))
            StudentList = cursor.fetchall()
            print(StudentList)

        self.loadStudents(StudentList)

    def loadStudents(self,StudentList):
        for i in self.tree.get_children():
            self.tree.delete(i)

        for student in StudentList:
            self.tree.insert("" , 0,values=(student[0],student[1],student[2],student[3],student[4],student[5],student[6],student[7],student[8]))

    def SaveChanges(self):
        valid = True
        self.message.set("")
        NFirstName = self.tFirstName.get()
        NLastName = self.tLastName.get()
        NHouseNumber = self.tHouseNumber.get()
        NStreetName = self.tStreetName.get()
        NTownOrCityName = self.tTownOrCityName.get()
        NPostCode = self.tPostCode.get()
        NEmail = self.tEmail.get()
        NMobilePhoneNumber = self.tMobilePhoneNumber.get()
        StudentID = self.tStudentID.get()
        if NFirstName == "" or NLastName == "" or NEmail == "" or NMobilePhoneNumber == "":
            valid = False
            self.message.set('missing details,first name,last name,phone number, email are all needed')
        if not Utilities.is_phone_number(NMobilePhoneNumber ):
            valid = False
            self.message.set('invalid mobile phone number')
        if not Utilities.is_postcode(NPostCode):
            valid = False
            self.message.set('invalid postcode')
        if not Utilities.is_email(NEmail):
            valid = False
            self.message.set('invalid email')
        if NHouseNumber != "":
            if int(NHouseNumber) < 0:
                self.message.set('invalid house number')
        if valid == True:
            with sqlite3.connect("GuitarLessons.db") as db:
                cursor = db.cursor()
                sql = "update tblStudents set FirstName =?,LastName=?,HouseNumber=?,StreetName=?,TownOrCityName=?,PostCode=?,Email=?,MobilePhoneNumber=? where StudentID=?"
                cursor.execute(sql,(NFirstName,NLastName,NHouseNumber,NStreetName,NTownOrCityName,NPostCode,NEmail,NMobilePhoneNumber,StudentID))
                db.commit()
            self.message.set("student details updated")

    def DeleteRecord(self):
        StudentID = self.tStudentID.get()
        #StudentID = int(StudentID)
        with sqlite3.connect("GuitarLessons.db") as db:
            cursor = db.cursor()
            sql = "delete from tblStudents where StudentID = ?"
            cursor.execute(sql,(StudentID))
            db.commit()
            self.tlabeupdate.set("student details deleted")

root = Tk()
root.title("booking system")
root.geometry("800x800")
root.configure(bg="white")
app = Application(root)

root.mainloop()

编辑 当我复制并粘贴我忘记放入原始帖子的其余代码时，我发现它只有在我通过学生菜单（单独的代码片段）打开它时才会停止工作，但如果我不通过它就可以工作菜单

Answer 1

您必须在根窗口上调用mainloop()，以便您的程序可以处理事件。

Answer 2

您在名为 root 的父级中创建 LabelFrames，但 root 不存在。要更正它，请将 master 传递给函数，该函数以 root 身份接收它

class Application():
    """ Binary to Decimal """ 
    def __init__(self, master):
        """ Initialize the frame. """
        self.create_GUI(master)

    def create_GUI(self, root):
        frame1 = tk.LabelFrame(root, text="frame1", width=300, height=130, bd=5)