Python:OpenFile dialog did not appear because of cannot access the text variable

I already created a button, an entry and a function for file dialog. After i press the 'browse' button the file dialog did not appear, so how can i make sure my custName.set(filename) can be use in my TracingMethod () function.

Steps for me to create a file dialog:

Step 1: import the file dialog from tkinter

from tkinter import filedialog

Step 2: Create the button and the entry

self.browseButton = Button(self.radioframe, text="Browse",command = self.open)
self.browseButton.grid(row =3, column =3, sticky = W)

#Define the entry
custName = StringVar(None)
location_ent =Entry(self.radioframe,textvariable = custName)
location_ent.grid(row =2, column = 2, sticky = W,columnspan=1)
location_ent.update()
location_ent.focus_set()

Step 3: Create the open() function [The IDE shows an error here]

def open():
    filename = filedialog.askopenfilename(parent=root,title='Choose a file')
    custName.set(filename)

What I am thinking is am I define the function outside the scoop? So I provide the full coding for reference.

from tkinter import *
from tkinter import filedialog

class TracingInterface(Frame):
    def __init__(self, master):
        super().__init__()
        master.minsize(width=700, height=520)
        master.maxsize(width=700, height=520)
        Grid.config(self)
        self.TracingMethod()
        self.logDetails()
        self.otherFunctionInterface()


    def TracingMethod(self):

        self.traceMethodSelect = StringVar()
        self.traceMethodSelect.set("LT")

        self.radioframe = LabelFrame(self,text="Tracing Method",height= 120,width =300)
        self.radioframe.grid(row= 0, column=0)
        self.radioframe.grid_propagate(0)

        self.radioframe.LT= Radiobutton(
        self.radioframe, text="Live Tracing",
        variable=self.traceMethodSelect, value="LT",
        anchor=W).grid(row=1, column = 0, sticky = W,columnspan=2)
        self.radioframe.SL= Radiobutton(
        self.radioframe, text="Specific Location",
        variable=self.traceMethodSelect, value="SL",
        anchor=W).grid(row=2, column = 0, sticky = W,columnspan=2)

        self.traceButton = Button(self.radioframe, text="Trace")
        self.traceButton.grid(row =3, column =0, sticky = W)

        self.cancelButton = Button(self.radioframe, text="Cancel")
        self.cancelButton.grid(row =3, column =1, sticky = W)

        self.configUAButton = Button(self.radioframe, text="Configuration",command=printMessage)
        self.configUAButton.grid(row =3, column =2, sticky = W)
        self.configUAButton.config(width=15)

        self.browseButton = Button(self.radioframe, text="Browse",command = self.open)
        self.browseButton.grid(row =3, column =3, sticky = W)

        custName = StringVar(None)
        location_ent =Entry(self.radioframe,textvariable = custName)
        location_ent.grid(row =2, column = 2, sticky = W,columnspan=1)
        location_ent.update()
        location_ent.focus_set()

    def logDetails(self):
        self.logframe = LabelFrame(self,text="Log Details",height= 520,width =390,padx=15)
        self.logframe.grid_propagate(0)

        self.logframe.grid_rowconfigure(0,weight =1)
        self.logframe.grid_columnconfigure(0,weight=1)

        xscrollbar = Scrollbar(self.logframe,orient = HORIZONTAL)
        xscrollbar.grid(row=1, column=1, sticky=E+W,columnspan=2)

        yscrollbar = Scrollbar(self.logframe,orient= VERTICAL)
        yscrollbar.grid(row=0, column=3, sticky=N+S)

        text = Text(self.logframe,width=50,height=50, wrap=NONE, xscrollcommand=xscrollbar.set,
                yscrollcommand=yscrollbar.set)
        text.grid(row=0, column=1, columnspan=2)
        # attach listbox to scrollbar
        xscrollbar.config(command=text.xview)
        yscrollbar.config(command=text.yview)

        button_1 = Button(self.logframe, text="View", command=printMessage,width =10)
        button_1.grid(row=2,column= 1)

        button_2 = Button(self.logframe, text="Export", command=printMessage,width =10)
        button_2.grid(row=2,column= 2)

        self.logframe.grid(row=0,column =1,rowspan=5)

    def otherFunctionInterface(self):
        self.otherFrame = LabelFrame(self,text="Other Function",height= 400,width =300)
        self.otherFrame.grid(row=4, column=0)
        self.otherFrame.grid_propagate(0)

        OpenPreviousCaseFile = Button(self.otherFrame, text="Open previous case file", command=printMessage,height = 4,
                                  width =21)
        OpenPreviousCaseFile.grid(row=5,column= 0,pady=5,padx=5)

        OpenPreviousTracingResult = Button(self.otherFrame, text="Open last tracing result ", command=printMessage,
                                       height = 4, width =21)
        OpenPreviousTracingResult.grid(row=6,column= 0,pady=5,padx=5)

        OpenMenualbtn = Button(self.otherFrame, text="User manual", command=printMessage,height =4, width =21)
        OpenMenualbtn.grid(row=7,column= 0,pady=5,padx=5)

        AboutBtn = Button(self.otherFrame, text="About", command=printMessage,height = 4, width =21)
        AboutBtn.grid(row=8,column= 0,pady=5,padx=5)

        locateCaseFile = Entry(self.otherFrame)
        locateCaseFile.grid(row=5,column = 1)

        locateTraceResult = Entry(self.otherFrame)
        locateTraceResult.grid(row=6,column = 1)
def open():
        filename = filedialog.askopenfilename(parent=root,title='Choose a file')
        custName.set(filename)


def     printMessage():
        print("Wow this actually worked!")

if __name__=='__main__':
    root=Tk()
    root.title("Windows User Activity History Tracing and Analysing System")
    tif= TracingInterface(root)
    root.mainloop()

Solution

self.browseButton widget does not appear because you set the columnspan option for location_ent to 1. You must modify it to 2 because you have self. configUAButton button there too.

This means you need to change:

location_ent.grid(row =2, column = 2, sticky = W,columnspan=1)

To:

location_ent.grid(row =2, column = 2, sticky = W,columnspan=2)

But you barely can self.browseButto now because the width you set for self.radioframe is not sufficient. So change this line:

self.radioframe = LabelFrame(self,text="Tracing Method",height= 120,width =300)

to:

self.radioframe = LabelFrame(self,text="Tracing Method",height= 120,width =355)

Of course, you will need to consequently modify the width option of master window. For this, change:

master.minsize(width=700, height=520)
master.maxsize(width=700, height=520)

Finally, you can not reach custName because you need to make it as an instance variable instead. This means you need to change:

self.custName = StringVar(None)
location_ent =Entry(self.radioframe,textvariable = self.custName)

To:

self.custName = StringVar(None)
location_ent =Entry(self.radioframe,textvariable = self.custName)

To:

master.minsize(width=755, height=520)
master.maxsize(width=755, height=520)

And (consequently) in open() method:

custName.set(filename)

To:

self.custName.set(filename)

Full program

Let us put all what is previously mentioned together:

from tkinter import *
from tkinter import filedialog

class TracingInterface(Frame):
    def __init__(self, master):
        super().__init__()
        master.minsize(width=755, height=520)
        master.maxsize(width=755, height=520)
        Grid.config(self)
        self.TracingMethod()
        self.logDetails()
        self.otherFunctionInterface()


    def TracingMethod(self):

        self.traceMethodSelect = StringVar()
        self.traceMethodSelect.set("LT")
        # Bill
        self.radioframe = LabelFrame(self,text="Tracing Method",height= 120,width =355)
        self.radioframe.grid(row= 0, column=0)
        self.radioframe.grid_propagate(0)

        self.radioframe.LT= Radiobutton(
        self.radioframe, text="Live Tracing",
        variable=self.traceMethodSelect, value="LT",
        anchor=W).grid(row=1, column = 0, sticky = W,columnspan=2)
        self.radioframe.SL= Radiobutton(
        self.radioframe, text="Specific Location",
        variable=self.traceMethodSelect, value="SL",
        anchor=W).grid(row=2, column = 0, sticky = W,columnspan=2)

        self.traceButton = Button(self.radioframe, text="Trace")
        self.traceButton.grid(row =3, column =0, sticky = W)

        self.cancelButton = Button(self.radioframe, text="Cancel")
        self.cancelButton.grid(row =3, column =1, sticky = W)

        self.configUAButton = Button(self.radioframe, text="Configuration",command=printMessage)
        self.configUAButton.grid(row =3, column =2, sticky = W)
        self.configUAButton.config(width=15)

        self.browseButton = Button(self.radioframe, text="Browse",command = self.open)
        self.browseButton.grid(row =3, column =3, sticky = W)
        # Bill
        self.custName = StringVar(None)
        location_ent =Entry(self.radioframe,textvariable = self.custName)
        # Bill
        location_ent.grid(row =2, column = 2, sticky = W,columnspan=2)
        location_ent.update()
        location_ent.focus_set()

    def logDetails(self):
        self.logframe = LabelFrame(self,text="Log Details",height= 520,width =390,padx=15)
        self.logframe.grid_propagate(0)

        self.logframe.grid_rowconfigure(0,weight =1)
        self.logframe.grid_columnconfigure(0,weight=1)

        xscrollbar = Scrollbar(self.logframe,orient = HORIZONTAL)
        xscrollbar.grid(row=1, column=1, sticky=E+W,columnspan=2)

        yscrollbar = Scrollbar(self.logframe,orient= VERTICAL)
        yscrollbar.grid(row=0, column=3, sticky=N+S)

        text = Text(self.logframe,width=50,height=50, wrap=NONE, xscrollcommand=xscrollbar.set,
                yscrollcommand=yscrollbar.set)
        text.grid(row=0, column=1, columnspan=2)
        # attach listbox to scrollbar
        xscrollbar.config(command=text.xview)
        yscrollbar.config(command=text.yview)

        button_1 = Button(self.logframe, text="View", command=printMessage,width =10)
        button_1.grid(row=2,column= 1)

        button_2 = Button(self.logframe, text="Export", command=printMessage,width =10)
        button_2.grid(row=2,column= 2)

        self.logframe.grid(row=0,column =1,rowspan=5)

    def otherFunctionInterface(self):
        self.otherFrame = LabelFrame(self,text="Other Function",height= 400,width =300)
        self.otherFrame.grid(row=4, column=0)
        self.otherFrame.grid_propagate(0)

        OpenPreviousCaseFile = Button(self.otherFrame, text="Open previous case file", command=printMessage,height = 4,
                                  width =21)
        OpenPreviousCaseFile.grid(row=5,column= 0,pady=5,padx=5)

        OpenPreviousTracingResult = Button(self.otherFrame, text="Open last tracing result ", command=printMessage,
                                       height = 4, width =21)
        OpenPreviousTracingResult.grid(row=6,column= 0,pady=5,padx=5)

        OpenMenualbtn = Button(self.otherFrame, text="User manual", command=printMessage,height =4, width =21)
        OpenMenualbtn.grid(row=7,column= 0,pady=5,padx=5)

        AboutBtn = Button(self.otherFrame, text="About", command=printMessage,height = 4, width =21)
        AboutBtn.grid(row=8,column= 0,pady=5,padx=5)

        locateCaseFile = Entry(self.otherFrame)
        locateCaseFile.grid(row=5,column = 1)

        locateTraceResult = Entry(self.otherFrame)
        locateTraceResult.grid(row=6,column = 1)
    def open(self):
        filename = filedialog.askopenfilename(parent=root,title='Choose a file')
        # Bill
        self.custName.set(filename)


def     printMessage():
        print("Wow this actually worked!")

if __name__=='__main__':
    root=Tk()
    root.title("Windows User Activity History Tracing and Analysing System")
    tif= TracingInterface(root)
    root.mainloop()

Demo

Here is a screenshot of the running above program: