AttributeError: StringVar instance has no attribute 'endswith' while trying to call from a Tkinter button

Question

I would like to create a GUI that receives two paths (a directory full of .txt documents and the destination of a new .csv file created from the files of the previously mentioned folder).

I am having trouble calling the function munge():

action = tk.Button(win, text="To .csv",command=munge(input_directory,output_directory))

Nevertheless, this exception raised:

/usr/local/Cellar/python/2.7.10_2/Frameworks/Python.framework/Versions/2.7/bin/python2.7 /Users/user/PycharmProjects/script.py
Traceback (most recent call last):
  File "/Users/user/PycharmProjects/script.py", line 82, in <module>
    action = tk.Button(win, text="To .csv", command=munge(input_directory,output_directory))
  File "/Users/user/PycharmProjects/script.py", line 39, in munge
    test = tuple(retrive(directory))
  File "/Users/user/PycharmProjects/script.py", line 31, in retrive
    for filename in sorted(glob.glob(os.path.join(directory_path, '*.txt'))):
  File "/usr/local/Cellar/python/2.7.10_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/posixpath.py", line 70, in join
    elif path == '' or path.endswith('/'):
AttributeError: StringVar instance has no attribute 'endswith'

Process finished with exit code 1

How can I correctly call the aforementioned function with the help of the Button widget?. I tried to set the name of the variable as indicated here question, but it did not worked.

update

Then from an answer of this question, I tried the following:

action = tk.Button(win, text="To .csv", command=lambda:munge(input_directory,output_directory))

Answer 1

Based on the error message, you seem to be trying to call the endswith method of a StringVar object. If you look at the documentation for such an object you'll see there's no such method. That is why you get the error that you do.

Assuming that path is an instance of a StringVar, you must call the get method in order to have the string stored by the object:

path_string = path.get()
if path_string == "" or path_string.endswith('/'):
    ...