Tkinter forgetting to finish the function - python-2.7

Question

I am again asking a question on this progressbar project; although this should just be a clarification question.
My code causes for a progressbar to be created to track the creation of a file. The user selects the type of file they want to create and then hits "go" which causes for the file to begin changing and for the progressbar to appear. Progressbar works great. File writing/manipulation works great.
Problem: When the user selects several files to manipulate, despite the progressbars being created correctly, they do NOT update correctly. At first I thought that clicking on a button multiple times causes for tkinter to forget the root.after() function it was doing previously but after playing with a (much simpler) sample code I realized that this is not the case.
Question: How do I make sure tkinter doesn't stop implementing the first function even when the same function is restarted with different parameters?
Below are parts of my code to describe what I am doing.
progbarlock = False # start with the prograssbar marked as not occupied
class guibuild:
def __init__(self):
self.root = root
guibuild.progbarlock = False
global theframe
theframe = Frame(root)
job_name = e.get()
label = Label(theframe,text = job_name).pack(side=LEFT,padx =2)
self.progbar = Meter(theframe) #makes the progressbar object
self.progbar.set(0.0) #sets the initial value to 0
self.progbar.pack(side=LEFT)
self.counter = 0
self.i = float(0) #i is the value set to the progressbar
def stop_progbar(self):
self.progbar.stop()
def begin(self):
self.interval()
self.Status_bar()
theframe.pack(anchor="s")
def interval(self):
if guibuild.progbarlock == False:
guibuild.progbarlock = True
def update(self):
the_file = open('running_file.json')
data = json.load(the_file)
curr = data["current_line"]
total = data["total_lines"]
if self.i == 1.0:
self.stop_progbar
rint "100% - process is done"
self.root.after_cancel(self.interval)
elif curr == self.counter:
self.root.after(5000, self.interval)
elif curr == self.counter+1:
self.i += 1.0/total
self.progbar.set(self.i) #apply the new value of i to the progressbar
self.counter += 1
self.stop_progbar
self.root.after(5000, self.interval)
elif curr > self.counter+1:
self.i += 1.0/total*(curr-self.counter)
self.progbar.set(self.i) #apply the new value of i to the progressbar
self.counter = curr
self.stop_progbar
self.root.after(5000, self.interval)
else:
print "something is wrong - running.json is not available"
self.root.after(5000, self.interval)
guibuild.progbarlock = False
def start_process():
makeRequest() #this is defined much earlier in the code and includes all the file creation and manipulation
guibuild().begin()
button4 = Button(root,text="GO", command = start_process).pack()
NOTE:makeRequest() depends entirely on user input and the user input changes each time "go" is pressed.