How can I create a python script that create a tkinter window. Inside this tkinter window is a text input box. Below it is a button that saves the text. Make the script for me and explain how it works. Also make sure the script is commented.
here is the script you requested:
```python
# this allows access to the Tcl/Tk GUI toolkit
import tkinter

# this creates the base window and assigns it to the variable root
root = tkinter.Tk()

# a text input box is called entry in tkinter, this code creates one and attaches it to the base window
entry = tkinter.Entry(root) 
entry.pack()

# this function retrieves the text from the previously created entry box and saves it to file input.txt
def saveEntryContent():
    # the open() function opens a file and returns it as a file object.
    with  open(input.txt, w) as file:
        # this retrieves the text inside of the entry box
        content = entry.get()
        # this writes the text to the file and then closes it
        file.write(content)
        file.close()

# this creates a button that is attached to the base window, sets the text on the button to save and makes the button call the function saveEntryContent when pressed
button = tkinter.Button(root, text =save, command = saveEntryContent)
button.pack()

# this makes the program loop until the user exits the window or waits for any events from the user.
root.mainloop()
```

this script creates a window with a text entry and a save button. when you press the save button, the script saves the contents of the entry to a file called input.txt. do you need me to explain any part in greater detail?
Can you tell me if this will overwrite the file input.txt, append to the file, or create it if it isn't there? Do I already have to have input.txt saved in the file system?
In this case the `open(input.txt, w)` command will overwrite input.txt, not appended to it.  If it does not exist, the file will be created.