Automatically turn off PC with Python and PyQt5

Question

I am a beginner in programming with Python. I am going to start my first job in this specialization. Can I use this code for presenting my skills at an interview?

import os 
import time
import datetime
import sys
from PyQt5 import QtWidgets, QtGui, QtCore
class MainForm(QtWidgets.QMainWindow):
 # atribute to save variable from time-edit widget, which is passed to the second window.
 saved_time = None
 def __init__(self, **kwargs):
 super().__init__(**kwargs)
 # settings of size and title
 self.setWindowTitle("TurnOff Aplikace")
 self.setGeometry(500, 300, 404, 280)
 self.setFixedSize(404, 280)
 # create stacked widget
 self.Qtstack = QtWidgets.QStackedWidget()
 self.setCentralWidget(self.Qtstack)
 # create two widget to stacked-widget
 self.stack1 = QtWidgets.QWidget()
 self.stack2 = QtWidgets.QWidget()
 # add widget to stacked widget
 self.Qtstack.addWidget(self.stack1)
 self.Qtstack.addWidget(self.stack2)
 # setting of layout to first stack
 self.layout_stack1 = QtWidgets.QVBoxLayout()
 self.stack1.setLayout(self.layout_stack1)
 # setting of layout to second stack
 self.layout_stack2 = QtWidgets.QVBoxLayout()
 self.stack2.setLayout(self.layout_stack2)
 # launch both windows
 self.show()
 self.front_window()
 self.back_window()
 
 def front_window(self): 
 
 # layout with text
 self.text = QtWidgets.QWidget()
 self.layout_text = QtWidgets.QHBoxLayout()
 self.text.setLayout(self.layout_text)
 self.layout_stack1.addWidget(self.text)
 self.layout_stack1.addStretch()
 # Layout to edit a checkboxs
 layout_edit = QtWidgets.QHBoxLayout()
 self.layout_stack1.addLayout(layout_edit)
 self.layout_stack1.addStretch()
 # Layout to error issue
 layout_error = QtWidgets.QHBoxLayout()
 self.layout_stack1.addLayout(layout_error)
 # Layout to pushbutton
 layout_button = QtWidgets.QHBoxLayout()
 self.layout_stack1.addLayout(layout_button)
 # widget with text
 self.text = QtWidgets.QLabel("Here you set how long it takes you to turn off the PC\nautomatically. You can also specify which monitor you want\nto switch to immediately. The minimum time is 15 minutes. \n\nNote: \nBefore turning off, the PC will automatically switch to the\nfirst monitor.")
 self.text.setFont(QtGui.QFont('Arial', 10)) 
 self.layout_text.addWidget(self.text)
 # Widget with time-edite
 layout_edit.addStretch()
 self.time_edit = QtWidgets.QTimeEdit(self)
 self.time_edit.setFont(QtGui.QFont('Arial', 16))
 layout_edit.addWidget(self.time_edit)
 # save time from edit-time to class variables
 self.saved_time = self.time_edit 
 # Widget s checkboxes
 layout_edit.addStretch()
 self.checkbox1 = QtWidgets.QCheckBox("1. monitor", self)
 self.checkbox1.setFont(QtGui.QFont('Arial', 10))
 layout_edit.addWidget(self.checkbox1)
 layout_edit.addStretch()
 self.checkbox2 = QtWidgets.QCheckBox("2. monitor", self)
 self.checkbox2.setFont(QtGui.QFont('Arial', 10))
 layout_edit.addWidget(self.checkbox2)
 layout_edit.addStretch()
 #widget s error issue
 self.error = QtWidgets.QLabel(self)
 self.error.setText("<font color='red'>minimum time is 15 minutes</font>")
 self.error.setFont(QtGui.QFont('Arial', 14))
 layout_error.addWidget(self.error)
 self.error.hide()
 # Widget with pushbutton
 self.Push_button_FW = QtWidgets.QPushButton("Enter", self)
 layout_button.addWidget(self.Push_button_FW)
 # logic with pushbutton
 self.Push_button_FW.clicked.connect(self.check_minimum_edit_time)
 # logic with checkboxs
 self.checkbox1.clicked.connect(self.checkbox_1_clicked)
 self.checkbox2.clicked.connect(self.checkbox_2_clicked)
 
 def back_window(self):
 # layout with text and countdown timer
 self.text_countdown = QtWidgets.QWidget()
 layout_text_countdown = QtWidgets.QHBoxLayout()
 self.text_countdown.setLayout(layout_text_countdown)
 self.layout_stack2.addWidget(self.text_countdown)
 # Layout with pushbutton
 button_layout = QtWidgets.QHBoxLayout()
 self.layout_stack2.addLayout(button_layout)
 # widget with text
 layout_text_countdown.addStretch()
 self.text = QtWidgets.QLabel("Automatic turning off the PC !!")
 self.text.setFont(QtGui.QFont('Arial', 10)) 
 layout_text_countdown.addWidget(self.text)
 layout_text_countdown.addStretch()
 # widget with countdown timer
 self.countdown = QtWidgets.QLabel(self)
 self.countdown.setFont(QtGui.QFont('Arial', 16))
 layout_text_countdown.addWidget(self.countdown)
 layout_text_countdown.addStretch()
 # Widget with pushbutton
 self.Push_button_BW = QtWidgets.QPushButton("Stop", self)
 button_layout.addWidget(self.Push_button_BW)
 # logic with pushbutton 
 self.Push_button_BW.clicked.connect(self.change_windows)
 self.Push_button_BW.clicked.connect(self.stop_countdown)
 
 def check_minimum_edit_time(self):
 """
 The function monitors whether the user has entered a minimum value in the countdown time.
 """
 given_time = self.time_edit.time()
 if given_time >= QtCore.QTime(0, 15):
 self.change_windows()
 self.start_countdown()
 self.change_monitor()
 else:
 self.error.show()
 def change_windows(self):
 """
 The function changes windows in the application.
 """
 if self.Qtstack.currentIndex() == 0:
 self.Qtstack.setCurrentIndex(1)
 elif self.Qtstack.currentIndex() == 1:
 self.Qtstack.setCurrentIndex(0)
 def change_monitor(self):
 """
 The function changes the output from the PC to the monitor.
 """
 if self.checkbox1.isChecked():
 os.system("DisplaySwitch.exe / internal")
 elif self.checkbox2.isChecked():
 os.system("DisplaySwitch.exe / external")
 
 def checkbox_1_clicked(self):
 """
 The function ensures that only one checkbox is unchecked at a time.
 """
 if self.checkbox1.isChecked():
 self.checkbox1.setChecked(True)
 self.checkbox2.setChecked(False)
 else:
 self.checkbox1.setChecked(False)
 def checkbox_2_clicked(self):
 """
 The function ensures that only one checkbox is unchecked at a time.
 """
 if self.checkbox2.isChecked():
 self.checkbox2.setChecked(True)
 self.checkbox1.setChecked(False)
 else:
 self.checkbox2.setChecked(False)
 
 def start_countdown(self):
 """
 The function starts the countdown when the ENTER button is clicked.
 """
 # create string from time
 string_time = self.saved_time.time().toString()
 # string pulls the time, but only in seconds, and stores a variable that is inserted into the function: timer_start ()
 x = time.strptime(string_time.split(',')[0],'%H:%M:%S')
 self.seconds = (datetime.timedelta(hours=x.tm_hour,minutes=x.tm_min,seconds=x.tm_sec).total_seconds())
 self.timer_start()
 def stop_countdown(self):
 """
 The function cancels the time countdown.
 """
 self.my_qtimer.stop()
 def timer_start(self):
 """
 The function sets the countdown.
 """
 self.time_left_int = self.seconds
 self.my_qtimer = QtCore.QTimer(self)
 self.my_qtimer.timeout.connect(self.timer_timeout)
 self.my_qtimer.start(1000)
 def timer_timeout(self):
 """
 The function sets the end of the countdown.
 """
 if self.time_left_int > 0:
 self.time_left_int -= 1
 self.update_number()
 else:
 self.my_qtimer.stop()
 os.system("shutdown / s / t 1")
 
 def update_number(self):
 """
 The function resets the number every second so that the user can see the countdown.
 """
 self.countdown.setText(str(datetime.timedelta(seconds=self.time_left_int)))
class App(QtWidgets.QApplication):
 def __init__(self):
 super().__init__(sys.argv)
 def build(self):
 self.main_window = MainForm()
 sys.exit(self.exec_())
root = App()
root.build()

• bfris: This is interesting code because I didn't know you could use Python to shut down a computer. But for an interview, it might not be that interesting to watch someone shut down their computer.
• Tomas: My first interview for programming job was successful with this code :D
• bfris: I stand corrected. Congratulations!

Answer 1

Don't mix locales

"Aplikace" seems to be Czech, where everything else is English. Choose one or the other consistently. If you want to switch between the two based on the system's locale that is also an option.

Stack switching

 if self.Qtstack.currentIndex() == 0:
 self.Qtstack.setCurrentIndex(1)
 elif self.Qtstack.currentIndex() == 1:
 self.Qtstack.setCurrentIndex(0)

can be

self.Qtstack.setCurrentIndex(
 1 - self.Qtstack.currentIndex()
)

No-op check

Does this actually have any effect?

 if self.checkbox1.isChecked():
 self.checkbox1.setChecked(True)
 else:
 self.checkbox1.setChecked(False)

I think the only thing that needs to be preserved there is the modification of checkbox2.

Time splitting

This:

time.strptime(string_time.split(',')[0],'%H:%M:%S')

is worrisome. Why is there a comma in that string? If it's actually because a comma precedes fractional seconds, then don't discard that section of the string using a split; instead include ,%f at the end of your format string.

Subprocess

Replace calls to os.system with calls to subprocess.

• Tomas: Thank you for your response. I would like to ask more about classes, because I dont know if what I wrote is good design due to functions which occur time in my app. Should I make a new class for them or is this ok ?
• Reinderien: The class layout seems fairly reasonable.