filedialog, tkinter and opening files

I'm working for the first time on coding a Browse button for a program in Python3. I've been searching the internet and this site, and even python standard library.

I have found sample code and very superficial explanations of things, but I haven't been able to find anything that addresses the problem I'm having directly, or a good enough explanation so I can customize code to my needs.

Here is the relevant snippet:

Button(self, text = "Browse", command = self.load_file, width = 10)\
        .grid(row = 1, column = 0, sticky = W) .....


 def load_file(self):

    filename = filedialog.askopenfilename(filetypes = (("Template files", "*.tplate")
                                                         ,("HTML files", "*.html;*.htm")
                                                         ,("All files", "*.*") ))
    if filename: 
        try: 
            self.settings["template"].set(filename)
        except: 
            messagebox.showerror("Open Source File", "Failed to read file \n'%s'"%filename)
            return

The method is a hybrid of some code I found along the way with my own customizations. It seems like I finally got it to work (kinda), though its not exactly how I need it.

I get this error when I activate the 'Browse' button: NameError: global name 'filedialog' is not defined.

I've found fairly similar issues along the way but all the solutions suggested I have covered. I went into the 'filedialog' help section of IDLE but didn't glean anything from there either.

Would someone mind providing a break down and a little guidance on this; none of my books address it specifically, and I've checked all the solutions provided to others—I'm lost.

The exception you get is telling you filedialog is not in your namespace. filedialog (and btw messagebox) is a tkinter module, so it is not imported just with from tkinter import *

>>> from tkinter import *
>>> filedialog
Traceback (most recent call last):
  File "<interactive input>", line 1, in <module>
NameError: name 'filedialog' is not defined
>>> 

you should use for example:

>>> from tkinter import filedialog
>>> filedialog
<module 'tkinter.filedialog' from 'C:\Python32\lib\tkinter\filedialog.py'>
>>>

or

>>> import tkinter.filedialog as fdialog

or

>>> from tkinter.filedialog import askopenfilename

So this would do for your browse button:

from tkinter import *
from tkinter.filedialog import askopenfilename
from tkinter.messagebox import showerror

class MyFrame(Frame):
    def __init__(self):
        Frame.__init__(self)
        self.master.title("Example")
        self.master.rowconfigure(5, weight=1)
        self.master.columnconfigure(5, weight=1)
        self.grid(sticky=W+E+N+S)

        self.button = Button(self, text="Browse", command=self.load_file, width=10)
        self.button.grid(row=1, column=0, sticky=W)

    def load_file(self):
        fname = askopenfilename(filetypes=(("Template files", "*.tplate"),
                                           ("HTML files", "*.html;*.htm"),
                                           ("All files", "*.*") ))
        if fname:
            try:
                print("""here it comes: self.settings["template"].set(fname)""")
            except:                     # <- naked except is a bad idea
                showerror("Open Source File", "Failed to read file\n'%s'" % fname)
            return


if __name__ == "__main__":
    MyFrame().mainloop()