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Use radiobuttons to determine a total charge
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Use radiobuttons to determine a total charge
#1
Question 
Hello. I am trying to write a GUI program that calculates total ticket prices. It allows the user to select a ticket category from a set of radiobuttons and enter the number of tickets into an Entry widget. Then an info dialog box displays the total charge. However, it just keeps displaying $0.0 as my total.

What am I doing wrong in my code? Why does it only display 0.0 and how can I display it with 2 decimal places?

The ticket prices are:
Senior: $7
Adult: $12
Child: $5

Here is my code:
import tkinter
import tkinter.messagebox


class TicketCalculatorGUI:
    def __init__(self):
        self.main_window = tkinter.Tk()
        self.main_window.title('Ticket Price Calculator')

        self.top_frame = tkinter.Frame(self.main_window)
        self.mid_frame = tkinter.Frame(self.main_window)
        self.bottom_frame = tkinter.Frame(self.main_window)

        self.radio_var1 = tkinter.IntVar()
        self.radio_var1.set(1)

        # create radio buttons in top frame
        self.rb_seniors = tkinter.Radiobutton(self.top_frame,
                                              text='Senior (>65)',
                                              variable=self.radio_var1,
                                              value=7)
        self.rb_adults = tkinter.Radiobutton(self.top_frame,
                                             text='Adult (15-65)',
                                             variable=self.radio_var1,
                                             value=12)
        self.rb_child = tkinter.Radiobutton(self.top_frame,
                                            text='Child (5-15)',
                                            variable=self.radio_var1,
                                            value=5)
        self.rb_seniors.pack()
        self.rb_adults.pack()
        self.rb_child.pack()

        # in mid frame use entry widget to get number of tickets
        self.prompt_label = tkinter.Label(self.mid_frame,
                                          text='Enter the number of tickets:')
        self.ticket_entry = tkinter.Entry(self.mid_frame,
                                          width=10)
        self.prompt_label.pack(side='left')
        self.ticket_entry.pack(side='left')

        # button in bottom frame should display total charges
        self.calc_button = tkinter.Button(self.bottom_frame,
                                          text='Display Charges',
                                          command=self.convert)
        self.quit_button = tkinter.Button(self.bottom_frame,
                                          text='Quit',
                                          command=self.main_window.destroy)
        self.calc_button.pack(side='left')
        self.quit_button.pack(side='left')

        self.top_frame.pack()
        self.mid_frame.pack()
        self.bottom_frame.pack()

        tkinter.mainloop()

    def convert(self):
        message = 'Your total charges = $'
        ticket = self.ticket_entry.get()
        total = 0.00
        senior = 7
        adult = 12
        child = 5

        if self.radio_var1.get() == 1:
            total = ticket * senior
        elif self.radio_var1.get() == 1:
            total = ticket * adult
        elif self.radio_var1.get() == 1:
            total = ticket * child

        tkinter.messagebox.showinfo('Total Charges', message + str(total))


if __name__ == '__main__':
    tickets = TicketCalculatorGUI()
The output in the dialog box is:
Output:
Your total charges = $0.0
I don't think I am supposed to do
if self.radio_var1.get() == 1:
            total = ticket * senior
What can I do different here?
Reply
#2
None of these are ever True
if self.radio_var1.get() == 1:
    total = ticket * senior
elif self.radio_var1.get() == 1:
    total = ticket * adult
elif self.radio_var1.get() == 1:
    total = ticket * child
Because in this code you set the possible values for radio_var1 to be 5, 7 or 12.
        self.rb_seniors = tkinter.Radiobutton(self.top_frame,
                                              text='Senior (>65)',
                                              variable=self.radio_var1,
                                              value=7)
        self.rb_adults = tkinter.Radiobutton(self.top_frame,
                                             text='Adult (15-65)',
                                             variable=self.radio_var1,
                                             value=12)
        self.rb_child = tkinter.Radiobutton(self.top_frame,
                                            text='Child (5-15)',
                                            variable=self.radio_var1,
                                            value=5)
You could change convert() to get the ticket value directly from radio_var1:
def convert(self):
    total = self.radio_var1.get() * self.ticket_entry.get()
    tkinter.messagebox.showinfo('Total Charges', message + str(total))
But I don't think it is a good idea to hardcode the ticket cost int the radio buttons.
SalsaBeanDip likes this post
Reply
#3
Thank you for the help. I was able to fix my problem

    def convert(self):
        message = 'Your total charges = $'
        ticket = self.ticket_entry.get()
        total = 0.00

        total = float(self.radio_var1.get()) * float(self.ticket_entry.get())
        tkinter.messagebox.showinfo('Total Charges', message + str(f'{total:.2f}'))
Reply


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