tk窗口未加载

Question

I'm currently working on a tk window python program for my project, but the tk window won't load and there is no error message in IDLE. Please help ! Thanks!

I've tried to switch position between showdata and label, but it seems like the label must be defined first b4 showdata, otherwise there will be error messages.

import tkinter as tk
import tkinter.scrolledtext as tkst
from quitButton import quitButton
from Student import Student
from tkinter.constants import LEFT

class Gui:

studentDL=[]

def __init__(self, root):

    self.root = root
    self.root.title("Simple Grading System")
    self.root.geometry('600x400')
    self.editArea = tkst.ScrolledText(self.root,height=5)
    self.editArea.pack(expand=1, fill="both")

    self.menuChoice = tk.IntVar()
    self.menuChoice.set(0)
    menuItems = [('Display all grade data',1),
                ('Display student\'s overall marks',2),
                 ('Display student\'s whose overall marks less than 40',3)]

    for (val, item) in enumerate(menuItems):
        tk.Radiobutton(self.root, 
              text=item[0],
              variable=self.menuChoice,
              command=self.showChoice,
              value=val).pack(anchor=tk.W)

    self.label = tk.Label(self.root, text='')
    self.label.pack(side=LEFT)
    self.showData()
    self.averagemark() 
    self.btnQ = quitButton(self.root)




def isNumber(self, s):
     try:
         float(s)
         return True
     except ValueError:
         return False

def showChoice(self):

    if self.menuChoice.get() == 0:
        self.showData()
    elif self.menuChoice.get() == 1:
        self.showGrade()
    elif self.menuChoice.get() == 2:
        self.showfail()

def showGrade(self):

    self.showData()

    self.editArea.delete(1.0, tk.END)    
    self.editArea.insert(tk.INSERT,('%-15s%-15s%10s%10s%10s\n'%
                                ('Student ID','Name','CW mark','Exam mark',
                                 'Overall')))
    self.editArea.insert(tk.INSERT,'='*60+'\n')

    for e in sorted(Gui.studentDL, key = lambda c: c.getname()):
        self.editArea.insert(tk.INSERT,e) 
        self.editArea.insert(tk.INSERT,'%10.2f'%e.overall()) 
        self.editArea.insert(tk.INSERT,'\n') 

def showData(self):

     try:

         fileIn = open('markdata.dat', 'r')

         Gui.studentDL=[]
         Student.numStudent = 0
         line = fileIn.readline()

         self.editArea.delete(1.0, tk.END)    
         self.editArea.insert(tk.INSERT,('%-15s%-20s%15s%15s\n'%('Student ID',
                                                            'Name',
                                                            'CW mark',
                                                            'Exam mark')))
         self.editArea.insert(tk.INSERT,'='*60+'\n')

         while line != '':
             Student.numStudent += 1
             studentRec=line.split('_')

             if len(studentRec) < 4:
                self.label['text']= 'Missing data : '+line+'\n'
             elif studentRec[0] == '' or studentRec[1] == '':
                self.label['text']= 'Invalid Student ID or Name : '+line+'\n'
             elif not self.isNumber(float(studentRec[2])):
                self.label['text']= 'Coursework marks are not numbers : '+line+'\n'  
             elif not self.isNumber(float(studentRec[3])):
                self.label['text']= 'Exam marks are not numbers : '+line+'\n'
             elif float(studentRec[2]) < 0 or float(studentRec[2]) > 100 :
                self.label['text']= 'Invalid Coursework marks : '+line+'\n'
             elif float(studentRec[3]) < 0 or float(studentRec[3]) > 100 :
                self.label['text']= 'Invalid Exam marks : '+line+'\n' 
             elif len(Gui.studentDL) == 0:
                self.label['text']= 'empty or invalid data only : '+line+'\n'


             else:
                   Gui.studentDL.append(Student(int(studentRec[0]),
                    studentRec[1],
                    float(studentRec[2]),
                    float(studentRec[3])))

                   self.editArea.insert(tk.INSERT,('%-10s%-20s%15.2f%15.2f\n'%(studentRec[0],
                                                            studentRec[1],
                                                            float(studentRec[2]),
                                                            float(studentRec[3]))))


             fileIn.close()

     except FileNotFoundError as error:
        self.label['text']= 'File is not found! Please Rectify.'

def showfail(self):

    self.showData()


    overall = 0


    self.editArea.delete(1.0, tk.END)
    self.editArea.insert(tk.INSERT,('%-15s%-15s%10s%10s%10s\n'%
                                ('Student ID','Name','CW mark','Exam ',
                                 'Overall')))
    self.editArea.insert(tk.INSERT,'='*60+'\n')

    for e in sorted(Gui.studentDL, key = lambda c: c.getname()):
        overall=e.overall()
        if overall<40:
            self.editArea.insert(tk.INSERT,e) 
            self.editArea.insert(tk.INSERT,'%10.2f'%e.overall()) 
            self.editArea.insert(tk.INSERT,'\n')



def averagemark(self):

    self.showData()

    total = 0
    overall = 0

    for e in sorted(Gui.studentDL, key = lambda c: c.getname()):
        overall += e.overall()
        total += 1

    average= overall/total

    self.label['text']= 'Average mark is :%10.2f'%average


def main():
    root = tk.Tk()
    Gui(root)
    root.mainloop()


if __name__ == '__main__':
    main()

for the quitbutton part:

import tkinter as tk

class quitButton(tk.Button):
    def __init__(self, parent):
        tk.Button.__init__(self, parent)
        self['text'] = 'Quit'
        self['command'] = parent.destroy
        self.pack(side=tk.BOTTOM)

def main():
    root = tk.Tk()
    quitButton(root)
    root.mainloop()

if __name__ == '__main__':
    main()

student class part:

class Student(object):

numStudent = 0 # class variable to record number of student
CWweight = 0.4
EXweight = 0.6


def __init__(self,studID,name,coursework,exam ):
    '''
    constructor method

    Parameters:
    - studID: student ID
    - name: name of student
    - coursework: coursework mark
    - exam: exam mark
    '''
    Student.numStudent += 1

    self.__studID = studID
    self.__name = name
    self.__coursework = coursework
    self.__exam = exam

def overall(self):
    '''
    calculate overall grade of student
    '''
    return self.getcoursework()*Student.CWweight + 
     self.getexam()*Student.EXweight

def __str__(self):
    '''
    String representation of student object
    '''
    return '%-15d%-15s%10.2f%10.2f'%\
    (self.getstudID(),self.getname(),self.getcoursework(),self.getexam())

def getstudID(self):

    return self.__studID

def getname(self):

    return self.__name

def getcoursework(self):

    return self.__coursework

def getexam(self):

    return self.__exam

my output markdata.dat:

50123456_lam tai man_70.0_60.0_
50223456_li tai man_60.0_90.5_
50323456_wong tai man_34.5_30.0_
50423456_ng tai man_90.5_70.0_
50523456_lau tai man_86.0_92.4_
50623456_chui tai man_70.0_64.5_
50723456_lim tai man_64.5_60.0_
50823456_pok tai man_37.5_35.50_
50923456_kim tai man_92.4_60.0_
50023456_tsang tai man_15.0_20.0_
50999999_chan peter_100.00_80.00_

Answer 1

Update:

After going over it in the comments it looks like your issue for not being able to start the program is your while loop in your showData method.

Here is a rewritten version of your code. It should start now thought I think you may have some other issues to work out with displaying data. I also moved studentDL into the class as a class attribute so it can be worked with internally. You were calling Gui.studentDL instead something like self.studentDL and I would say using it as a class attribute is better here.

import tkinter as tk
import tkinter.scrolledtext as tkst
#from quitButton import quitButton
#from Student import Student
from tkinter.constants import LEFT


class quitButton(tk.Button):
    def __init__(self, parent):
        tk.Button.__init__(self, parent)
        self['text'] = 'Quit'
        self['command'] = parent.destroy
        self.pack(side=tk.BOTTOM)


class Student(object):
    numStudent = 0 # class variable to record number of student
    CWweight = 0.4
    EXweight = 0.6    
    def __init__(self, studID, name, coursework, exam):
        Student.numStudent += 1
        self.__studID = studID
        self.__name = name
        self.__coursework = coursework
        self.__exam = exam

    def overall(self):
        return self.getcoursework() * Student.CWweight + self.getexam() * Student.EXweight

    def __str__(self):
        return '%-15d%-15s%10.2f%10.2f'%(self.getstudID(), self.getname(), self.getcoursework(), self.getexam())

    def getstudID(self):
        return self.__studID

    def getname(self):
        return self.__name

    def getcoursework(self):
        return self.__coursework

    def getexam(self):
        return self.__exam


class Gui:
    def __init__(self, root):
        self.root = root
        self.studentDL = []
        self.root.title("Simple Grading System")
        self.root.geometry('600x400')
        self.editArea = tkst.ScrolledText(self.root, height=5)
        self.editArea.pack(expand=1, fill="both")
        self.menuChoice = tk.IntVar()
        self.menuChoice.set(0)
        menuItems = [('Display all grade data', 1), ('Display student\'s overall marks', 2), ('Display student\'s whose overall marks less than 40', 3)]

        for (val, item) in enumerate(menuItems):
            tk.Radiobutton(self.root, text=item[0], variable=self.menuChoice, command=self.showChoice, value=val).pack(anchor=tk.W)

        self.label = tk.Label(self.root, text='')
        self.label.pack(side=LEFT)
        self.showData()
        self.averagemark()
        self.btnQ = quitButton(self.root)

    def isNumber(self, s):
        try:
            float(s)
            return True
        except ValueError:
            return False

    def showChoice(self):
        if self.menuChoice.get() == 0:
            self.showData()
        elif self.menuChoice.get() == 1:
            self.showGrade()
        elif self.menuChoice.get() == 2:
            self.showfail()

    def showGrade(self):
        self.showData()
        self.editArea.delete(1.0, tk.END)    
        self.editArea.insert(tk.INSERT, ('%-15s%-15s%10s%10s%10s\n' % ('Student ID', 'Name', 'CW mark', 'Exam mark', 'Overall')))
        self.editArea.insert(tk.INSERT, '=' * 60 + '\n')

        for e in sorted(self.studentDL, key = lambda c: c.getname()):
            self.editArea.insert(tk.INSERT, e) 
            self.editArea.insert(tk.INSERT, '%10.2f' % e.overall()) 
            self.editArea.insert(tk.INSERT, '\n') 

    def showData(self):
        try:
            with open('markdata.dat', 'r') as fileIn:
                self.studentDL = []
                Student.numStudent = 0

                self.editArea.delete(1.0, tk.END)    
                self.editArea.insert(tk.INSERT, ('%-15s%-20s%15s%15s\n' % ('Student ID', 'Name', 'CW mark', 'Exam mark')))
                self.editArea.insert(tk.INSERT, '=' * 60 + '\n')

                for line in fileIn:
                    Student.numStudent += 1
                    studentRec=line.split('_')
                    if len(studentRec) < 4:
                        self.label['text'] = 'Missing data : ' + line + '\n'
                    elif studentRec[0] == '' or studentRec[1] == '':
                        self.label['text'] = 'Invalid Student ID or Name : ' + line + '\n'
                    elif not self.isNumber(float(studentRec[2])):
                        self.label['text'] = 'Coursework marks are not numbers : ' + line + '\n'  
                    elif not self.isNumber(float(studentRec[3])):
                        self.label['text'] = 'Exam marks are not numbers : ' + line + '\n'
                    elif float(studentRec[2]) < 0 or float(studentRec[2]) > 100 :
                        self.label['text'] = 'Invalid Coursework marks : ' + line + '\n'
                    elif float(studentRec[3]) < 0 or float(studentRec[3]) > 100 :
                        self.label['text'] = 'Invalid Exam marks : ' + line + '\n' 
                    elif len(self.studentDL) == 0:
                        self.label['text'] = 'empty or invalid data only : ' + line + '\n'


                    else:
                        self.studentDL.append(Student(int(studentRec[0]), studentRec[1],
                                            float(studentRec[2]), float(studentRec[3])))
                        self.editArea.insert(tk.INSERT, ('%-10s%-20s%15.2f%15.2f\n' % (studentRec[0], studentRec[1],
                                            float(studentRec[2]), float(studentRec[3]))))

        except FileNotFoundError as error:
            print("Failed to open markdata")
            self.label['text'] = 'File is not found! Please Rectify.'

    def showfail(self):
        self.showData()
        overall = 0
        self.editArea.delete(1.0, tk.END)
        self.editArea.insert(tk.INSERT, ('%-15s%-15s%10s%10s%10s\n' % ('Student ID', 'Name', 'CW mark', 'Exam ', 'Overall')))
        self.editArea.insert(tk.INSERT, '=' * 60 + '\n')

        for e in sorted(self.studentDL, key = lambda c: c.getname()):
            overall = e.overall()
            if overall<40:
                self.editArea.insert(tk.INSERT, e)
                self.editArea.insert(tk.INSERT, '%10.2f' % e.overall())
                self.editArea.insert(tk.INSERT, '\n')

    def averagemark(self):
        self.showData()
        total = 0
        overall = 0
        for e in sorted(self.studentDL, key = lambda c: c.getname()):
            overall += e.overall()
            total += 1
        # added if statement to deal with dividing by zero
        if overall != 0 or total != 0:
            average = overall / total
        else:
            average = 0

        self.label['text'] = 'Average mark is :%10.2f' % average


if __name__ == '__main__':
    root = tk.Tk()
    my_gui = Gui(root)
    root.mainloop()