PYTHON CSV GUI

from tkinter import *
import sys

#define the labels of the fileds
fields = 'Reference', 'CL', 'INV', 'Date1', 'Date2'
#define how the fields work
def fetch(entries):
   for entry in entries:
      field = entry[0]
      text  = entry[1].get()
      print('%s: "%s"' % (field, text))

def makeform(root, fields):
   entries = []
   for field in fields:
      row = Frame(root)
      lab = Label(row, width=15, text=field, anchor='w')
      ent = Entry(row)
      row.pack(side=TOP, fill=X, padx=5, pady=5)
      lab.pack(side=LEFT)
      ent.pack(side=RIGHT, expand=YES, fill=X)
      entries.append((field, ent))
   return entries

def quit(root):
    root.destroy()
    sys.exit()

def save_file():
    file_name =  filedialog.asksaveasfilename(initialdir = __file__,title = "Select file")
    #insert function to save the file as file_name
    print(file_name)

def open_file():
	open_file = tkFileDialog.askopenfilename(initialdir = "/",title = "Select file",filetypes = (("csv files","*.csv"),("all files","*.*")))
	print (open_file)

if __name__ == '__main__':
   root = Tk()
   ents = makeform(root, fields)
   root.bind('<Return>', (lambda event, e=ents: fetch(e)))
   #button 1 - not set to open
   b1 = button (root, text='Open',command=lambda: open_file())
   b1.pack(side=LEFT, padx=5, pady=5)
   b2 = Button(root, text='Run', command=(lambda e=ents: fetch(e)))
   b2.pack(side=LEFT, padx=5, pady=5)
   #button 2 - dies not function accordingly
   b3 = Button(root, text='Save', command=lambda: save_file())
   b3.pack(side=LEFT, padx=5, pady=5)
   b4 = Button(root, text='Quit', command=lambda: quit(root))
   b4.pack(side=LEFT, padx=5, pady=5)
   root.mainloop()