Tkinter Exit Code based on Entry Widget

[deanhystad]

Based on these assumptions:

input 5 starts the test
input 6 determines if the test fails or passes

You could do something like this:

import enum

class TestState(enum.Enum):
    '''States for testing state machine'''
    Unknown = 0,    # Figure out what the new state should be
    NotReady = 1,   # Need to enter badge number before testing
    Ready = 2,      # Badge entered.  Waiting for test button press
    Testing = 3,    # Running test.
    Completed = 4   # Test completed.  Wait for test button release

class App(Frame):
 
    def __init__(self,master=None):
        ...
        self.tester = ''
        self.time = ''
        self.set_state(TestState.Unknown)
        self.update_clock()

    def set_state(self, new_state):
        '''Testing state machine.  See states above'''
        if new_state == TestState.NotReady:
            # Report we are not ready for testing
            self.label.configure('Test Not Ready')
        if new_state == TestState.Ready:
            # Report we are ready for testing
            self.label.configure('Test Ready')
        if new_state == TestState.Testing:
            # Perform the test and report results
            result = ('FAILED', 'PASSED)[GPIO.input(6)]
            self.label.configure(f'blah blah blah Test {result} blah blah')
            with open(self.test_file, "a") as f: # open file
                f.write(f"Badge#{self.teste}, Test {result} ON: {self.time}n')
            # Erase test results after 4 seconds
            self.after(4000, lambda: self.set_state(TestState.Completed))
        self.state = new_state

    def update_clock(self):
        '''Runs periodically'''
        ...
        self.tester = self.entry_widget.get()
        self.time = some date-time string
        ...
        if self.state == TestState.Unknown:
            if len(self.tester) == 0:
                self.set_state(TestState.NotReady)
            else:
                self.set_state(TestState.Ready)
        if self.state == TestState.NotReady:
            # Waiting for tester to enter badge number
            if len(self.tester) > 0:
                self.set_state(TestState.Ready)
        if self.state == TestState.Ready:
            # Waiting for test button.  Can also go to not-ready if 
            if len(self.tester) == 0:
                self.set_state(TestState.NotReady)
            elif GPIO.input(5) == 1:
                self.set_state(TestState.Testing)
        if self.state == TestState.Completed:
            # Begin new test sequence when test button is released
            if GPIO.input(5) == 0:
                self.set_state(TestState.Unknown)
    
        # Update frequently to be responsive to button press
        self.after(100, lambda: self.update_clock)

This implements a "state machine" that has the states:
Unknown: Current state is not known
NotReady: Waiting for badge number to be entered
Ready: Badge number entered and waiting for test button
Testing: Performing a test
Completed: Test is finished

We transition from one state to another when events occur. The transitions are (Transiton: Event):
Unknown->NotReady: Badge number is not entered
Unknown->Ready: Badge number is entered
NotReady->Ready: Badge number is entered
Ready->NotReady: Badge number is not entered
Ready->Testing: Test button is pressed
Testing->Completed: Test finished and 4 seconds passed
Completed->Unknown: Automatic

When we transition to a new state we perform some actions. The actions are:
Ready: Update status label
NotReady: Update status label
Testing: Run test. Record results. Update status label. Schedule transition to Unknown after 4 seconds

Since actions are only performed when the state changes you don't have to worry about recording the same results multiple times for one test or writing the test results over the Test Ready message. Most of the time your software will be do nothing but wait for an event.