This is a simple countdown widget for Python, implemented with tkinter. As tkinter is part of the Python standard library, no additional sources are required. Calling the start() method launches a separate process which runs the gui thread. After the countdown finishes, the process terminates.
Usage example:
from CountdownWidget import CountdownWidget
if __name__ == "__main__":
countdownWidget = CountdownWidget(countdownMs = 10000)
countdownWidget.start()