Calling of variable in python

Python provides nested scopes (which may be what you're after) but it does provide one function with access to local variables of another function at the same level. If the latter is what you need, consider using a global variable.

See the tutorial for a discussion of scoping. Also, see the language reference for a discussion of global declarations.

In the following example, global is used to declare a variable that can be accesses and written in two different functions:

def f():
    global x
    x = 1

def g():
    global x
    x = 2

Here is an example of a nested scope where an inner function can read but not write a variable in an enclosing function:

def f():
    x = 1
    def g():
        print(x)
    return g

In Python 3, the nonlocal keyword was added to support writing to x from the inner function:

def f():
    x = 1
    def g():
        nonlocal x
        x += 1
    g()
    print(x)

Rather thank mucking around with global keyword, your class methods need to be bound to the parent object. Looks like you really need to work through a tutorial about python's scoping rules.

  class Copy(object):
    def __init__(self):
      # don't define further methods in here!

    def srce(self):
      self.src = ...

    def dest(self):
      self.des = ..

    def start(self):
      #Here you can access self.des and self.src

import sys
import os
import tkMessageBox
from Tkinter import *
from tkCommonDialog import Dialog
import shutil
import tkFileDialog
import win32com.client

win = Tk()
win.title("Copying the Directory to specified location")
win.geometry("600x600+200+50")
win.resizable()


class Copy(object):


    def __init__(self):
        def srce():

            self.src = tkFileDialog.askdirectory(title="The source folder is ")
            textboxsrc.delete(0, END)
            textboxsrc.insert(0, self.src)
            print self.src
            return self.src

        textboxsrc = Entry(win, width="70")
        textboxsrc.insert(0, 'Enter master file name')
        textboxsrc.pack()
        textboxsrc.place(relx=0.40, rely=0.06, anchor=CENTER)
        bu = Button(text="Source", font="Verdana 12 italic bold", bg="Purple", fg="white", command=srce)
        bu.pack(fill=X, expand=YES)
        bu.place(relx=0.85, rely=0.06, anchor=CENTER)

        def dest():
            self.des = tkFileDialog.askdirectory(title="TheDestination folder is ")
            textboxdes.delete(0, END)
            textboxdes.insert(0, self.des)
            print self.des
            return self.des

        textboxdes = Entry(win, width="70")
        textboxdes.insert(0, 'Enter master file name')
        textboxdes.pack()
        textboxdes.place(relx=0.40, rely=0.13, anchor=CENTER)
        bu1 = Button(text="Destination", font="Verdana 12 italic", bg="Purple", fg="white", command=dest)
        bu1.pack(fill=X, expand=YES)
        bu1.place(relx=0.85, rely=0.13, anchor=CENTER)

        def start():


            try:
                shutil.copytree(self.src, self.des)
            except :
                tkMessageBox.showwarning("Copying file", "Error while copying\n(%s)")

        bn = Button(text="Copy", font="Verdana 12 italic", bg="Purple", fg="white", command=start)
        bn.pack(fill=X, expand=YES)
        bn.place(relx=0.50, rely=0.25, anchor=CENTER)

obj = Copy()
#obj.source(win)
#obj.destination(win)
win.mainloop()