from tkinter import * from functools import partial # To prevent unwanted windows import all_constants as c import conversion_rounding as cr class Converter: """ Temperature conversion tool (°C to °F or °F to °C) """ def __init__(self): """ Temperature converter GUI """ self.all_calculations_list = [] self.temp_frame = Frame(padx=10, pady=10) self.temp_frame.grid() self.temp_heading = Label(self.temp_frame, text="Temperature Convertor", font=("Arial", "16", "bold")) self.temp_heading.grid(row=0) instructions = ("Please enter a temperature below and then press one of the buttons to convert it from " "centigrade to fahrenheit.") self.temp_instructions = Label(self.temp_frame, text=instructions, wraplength=250, width=40, justify="left") self.temp_instructions.grid(row=1) self.temp_entry = Entry(self.temp_frame, font=("Arial", "14") ) self.temp_entry.grid(row=2, padx=18, pady=10) error = "Please enter a number" self.answer_error = Label(self.temp_frame, text=error, fg="#004C99") self.answer_error.grid(row=3) # Conversion, help and history / export buttons self.button_frame = Frame(self.temp_frame) self.button_frame.grid(row=4) # button list (button text | bg colour |command | row | column) button_details_list = [ ["To Celsius", "#990099", lambda: self.check_temp(c.ABS_ZERO_FAHRENHEIT), 0, 0], ["To Fahrenheit", "#009900", lambda: self.check_temp(c.ABS_ZERO_CELSIUS), 0, 1], ["Help / Info", "#CC6600", self.to_help, 1, 0], ["History / Export", "#004C99", "", 1, 1] ] # List to hold buttons once they have been made self.button_ref_list = [] for item in button_details_list: self.make_button = Button(self.button_frame, text=item[0], bg=item[1], fg="#FFFFFF", font=("Arial", "12", "bold"), width=12, command=item[2]) self.make_button.grid(row=item[3], column=item[4], padx=5, pady=5) self.button_ref_list.append(self.make_button) # Retrieve to_help button self.to_help_button = self.button_ref_list[2] # Retrieve 'history / export' button and disable it at the start self.to_history_button = self.button_ref_list[3] self.to_history_button.config(state=DISABLED) def check_temp(self, min_temp): """ Checks temperature is valid and either invokes calculation function or shows a custom error """ # Retrieve temperature to be converted to_convert = self.temp_entry.get() # Reset label and entry box (if we had an error) self.answer_error.config(fg="#004C99") self.temp_entry.config(bg="#FFFFFF") # Checks that amount to be converted is a number above absolute zero try: to_convert = float(to_convert) if to_convert >= min_temp: error = "" self.convert(min_temp, to_convert) else: error = f"Enter a number more than / equal to {min_temp}" except ValueError: error = "Please enter a number" # Display the error if necessary if error != "": self.answer_error.config(text=error, fg="#9C0000") self.temp_entry.config(bg="#F4CCCC") self.temp_entry.delete(0, END) def convert(self, min_temp, to_convert): """ Converts temperatures and updates answer label. Also stores calculations for Export / History feature """ if min_temp == c.ABS_ZERO_CELSIUS: answer = cr.to_fahrenheit(to_convert) answer_statement = f"{to_convert}°C is {answer} °F" else: answer = cr.to_celsius(to_convert) answer_statement = f"{to_convert} °F is {answer} °C" # Enable history export button as soon as we have a valid calculation self.to_history_button.config(state=NORMAL) self.answer_error.config(text=answer_statement) self.all_calculations_list.append(answer_statement) print(self.all_calculations_list) def to_help(self): """ Opens help dialogue box and disables help button (so that users can't create multiple help boxes) """ Converter.DisplayHelp(self) class DisplayHelp: """ Displays help dialogue box """ def __init__(self, partner): # setup dialogue box and background colour background = "#ffe6cc" self.help_box = Toplevel() # disable help button partner.to_help_button.config(state=DISABLED) # If users press cross at top, closes help and 'releases' help button self.help_box.protocol('WM_DELETE_WINDOW', partial(self.close_help, partner)) self.help_frame = Frame(self.help_box, width=300, height=200) self.help_frame.grid() self.help_heading_label = Label(self.help_frame, text="Help / Info", font=("Arial", "14", "bold")) self.help_heading_label.grid(row=0) help_text = ( "To use the program, simply enter the temperature " "you wish to convert and then choose to convert " "to either degrees Celsius (centigrade) or " "Fahrenheit.\n\n" "Note that -273 degrees C " "(-459 F) is absolute zero (the coldest possible " "temperature). If you try to convert a " "temperature that is less than -273 degrees C, " "you will get an error message.\n\n" "To see your calculation history and export it to a text " "file, please click the 'History / Export' button." ) self.help_text_label = Label( self.help_frame, text=help_text, wraplength=350, justify="left" ) self.help_text_label.grid(row=1, padx=10) self.dismiss_button = Button(self.help_frame, font=("Arial", "12", "bold"), text="Dismiss", bg="#CC6600", fg="#FFFFFF", command=partial(self.close_help, partner)) self.dismiss_button.grid(row=2, padx=10, pady=10) # List and loop to set background colour on # everything except the buttons. recolour_list = [self.help_frame, self.help_heading_label, self.help_text_label] for item in recolour_list: item.config(bg=background) def close_help(self, partner): """ Closes help dialogue box (and enables help button) """ # Put help button back to normal partner.to_help_button.config(state=NORMAL) self.help_box.destroy() # main routine if __name__ == "__main__": root = Tk() root.title("Temperature converter") Converter() root.mainloop()