{"id":1499,"date":"2020-12-07T07:39:26","date_gmt":"2020-12-07T07:39:26","guid":{"rendered":"https:\/\/www.pythontutorial.net\/?page_id=1499"},"modified":"2020-12-11T01:13:56","modified_gmt":"2020-12-11T01:13:56","slug":"tkinter-example","status":"publish","type":"page","link":"https:\/\/www.pythontutorial.net\/tkinter\/tkinter-example\/","title":{"rendered":"Tkinter Example"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you’ll learn how to build a Tkinter temperature converter application.<\/p>\n\n\n\n

Introduction to the Temperature Converter application #<\/a><\/h2>\n\n\n\n

The following shows the Temperature Converter application that you’re going to build. The application converts a temperature from Fahrenheit to Celsius:<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

Basically, the application has a label<\/a>, an entry<\/a>, and a button<\/a>. When you enter a temperature in Fahrenheit and click the Convert<\/code> button, it’ll convert the value in the textbox from Fahrenheit to Celsius.<\/p>\n\n\n\n

If you enter a value that cannot be converted to a number, the program will show an error.<\/p>\n\n\n\n

To build this application, you follow these steps.<\/p>\n\n\n\n

First, import the tkinter<\/code> module, ttk<\/code> submodule, and the showerror<\/code> function from tkinter.messagebox<\/code>:<\/p>\n\n\n

import<\/span> tkinter as<\/span> tk\nfrom<\/span> tkinter import<\/span> ttk\nfrom<\/span> tkinter.messagebox import<\/span> showerror<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Second, create the root window and set its configurations:<\/p>\n\n\n
# root window<\/span>\nroot = tk.Tk()\nroot.title('Temperature Converter'<\/span>)\nroot.geometry('300x70'<\/span>)\nroot.resizable(False<\/span>, False<\/span>)\n<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Third, define a function that converts a temperature from Fahrenheit to Celsius:<\/p>\n\n\n
def<\/span> fahrenheit_to_celsius<\/span>(f)<\/span>:<\/span>\n    \"\"\" Convert fahrenheit to celsius\n    \"\"\"<\/span>\n    return<\/span> (f - 32<\/span>) * 5<\/span>\/9<\/span>\n<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
frame = ttk.Frame(root)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Fifth, define an option that will be used by all the form fields:<\/p>\n\n\n
options = {'padx'<\/span>: 5<\/span>, 'pady'<\/span>: 5<\/span>}<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Sixth, define the label, entry, and button. The label will show the result once you click the Convert<\/code> button:<\/p>\n\n\n
# temperature label<\/span>\ntemperature_label = ttk.Label(frame, text='Fahrenheit'<\/span>)\ntemperature_label.grid(column=0<\/span>, row=0<\/span>, sticky='W'<\/span>, **options)\n\n# temperature entry<\/span>\ntemperature_entry = ttk.Entry(frame, textvariable=temperature)\ntemperature_entry.grid(column=1<\/span>, row=0<\/span>, **options)\ntemperature_entry.focus()\n\n# convert button<\/span>\nconvert_button = ttk.Button(frame, text='Convert'<\/span>)\nconvert_button.grid(column=2<\/span>, row=0<\/span>, sticky='W'<\/span>, **options)\nconvert_button.configure(command=convert_button_clicked)\n\n# result label<\/span>\nresult_label = ttk.Label(frame)\nresult_label.grid(row=1<\/span>, columnspan=3<\/span>, **options)<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Finally, place the frame on the root window and run the mainloop()<\/code> method:<\/p>\n\n\n
frame.grid(padx=10<\/span>, pady=10<\/span>)\nroot.mainloop()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
Put it all together.<\/p>\n\n\n
import<\/span> tkinter as<\/span> tk\nfrom<\/span> tkinter import<\/span> ttk\nfrom<\/span> tkinter.messagebox import<\/span> showerror\n\n# root window<\/span>\nroot = tk.Tk()\nroot.title('Temperature Converter'<\/span>)\nroot.geometry('300x70'<\/span>)\nroot.resizable(False<\/span>, False<\/span>)\n\n\ndef<\/span> fahrenheit_to_celsius<\/span>(f)<\/span>:<\/span>\n    \"\"\" Convert fahrenheit to celsius\n    \"\"\"<\/span>\n    return<\/span> (f - 32<\/span>) * 5<\/span>\/9<\/span>\n\n\n# frame<\/span>\nframe = ttk.Frame(root)\n\n\n# field options<\/span>\noptions = {'padx'<\/span>: 5<\/span>, 'pady'<\/span>: 5<\/span>}\n\n# temperature label<\/span>\ntemperature_label = ttk.Label(frame, text='Fahrenheit'<\/span>)\ntemperature_label.grid(column=0<\/span>, row=0<\/span>, sticky='W'<\/span>, **options)\n\n# temperature entry<\/span>\ntemperature = tk.StringVar()\ntemperature_entry = ttk.Entry(frame, textvariable=temperature)\ntemperature_entry.grid(column=1<\/span>, row=0<\/span>, **options)\ntemperature_entry.focus()\n\n# convert button<\/span>\n\n\ndef<\/span> convert_button_clicked<\/span>()<\/span>:<\/span>\n    \"\"\"  Handle convert button click event \n    \"\"\"<\/span>\n    try<\/span>:\n        f = float(temperature.get())\n        c = fahrenheit_to_celsius(f)\n        result = f'{f}<\/span> Fahrenheit = {c:.2<\/span>f}<\/span> Celsius'<\/span>\n        result_label.config(text=result)\n    except<\/span> ValueError as<\/span> error:\n        showerror(title='Error'<\/span>, message=error)\n\n\nconvert_button = ttk.Button(frame, text='Convert'<\/span>)\nconvert_button.grid(column=2<\/span>, row=0<\/span>, sticky='W'<\/span>, **options)\nconvert_button.configure(command=convert_button_clicked)\n\n# result label<\/span>\nresult_label = ttk.Label(frame)\nresult_label.grid(row=1<\/span>, columnspan=3<\/span>, **options)\n\n# add padding to the frame and show it<\/span>\nframe.grid(padx=10<\/span>, pady=10<\/span>)\n\n\n# start the app<\/span>\nroot.mainloop()<\/code><\/span>Code language:<\/span> Python<\/span> (<\/span>python<\/span>)<\/span><\/small><\/pre>\n\n\n
In this tutorial, you’ve learned how to develop a simple Tkinter application that converts a temperature from Fahrenheit to Celsius.<\/p>\n
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Fourth, create a frame<\/a> that holds form fields:<\/p>\n\n\n