Python Tkinter GUI Tutorial: Building Windows, Widgets, and Event Handling

We start by importing the tkinter package, creating a Tk window, and setting its title.

To display a simple label, we instantiate Label with the window as its parent and call grid to position it.

<code>from tkinter import *
window = Tk()
window.title("First Window")
window.mainloop()</code>

Adding a label widget involves creating a Label instance and placing it with grid :

<code>lbl = Label(window, text="Hello")
lbl.grid(column=0, row=0)</code>

We can change the label's font size using the font parameter:

<code>lbl = Label(window, text="Hello", font=("Arial Bold", 50))</code>

The window size is adjusted with the geometry method, e.g., window.geometry("350x200") .

Buttons are created similarly with Button and positioned via grid . To respond to clicks, define a function and assign it to the button's command attribute.

<code>def clicked():
    lbl.configure(text="Button was clicked!")
btn = Button(window, text="Click Me", command=clicked)
btn.grid(column=1, row=0)</code>

An Entry widget captures user input; its get method retrieves the text, which can be displayed in the label inside the click handler.

<code>txt = Entry(window, width=10)
txt.grid(column=1, row=0)
def clicked():
    res = "Welcome to " + txt.get()
    lbl.configure(text=res)</code>

Focus can be set directly on the entry widget with txt.focus() so the user can type immediately.

A Combobox (from tkinter.ttk ) provides a drop‑down list; values are set via the ['values'] attribute, and the default selection with current() .

<code>from tkinter.ttk import *
combo = Combobox(window)
combo['values'] = (1, 2, 3, 4, 5, "Text")
combo.current(1)
combo.grid(column=0, row=0)</code>

Checkbuttons use a variable such as BooleanVar or IntVar to store their state:

<code>chk_state = BooleanVar()
chk_state.set(True)
chk = Checkbutton(window, text="Choose", var=chk_state)
chk.grid(column=0, row=0)</code>

Radiobuttons share an IntVar variable to ensure only one is selected, and their values can be retrieved with get() :

<code>selected = IntVar()
rad1 = Radiobutton(window, text="First", value=1, variable=selected)
rad2 = Radiobutton(window, text="Second", value=2, variable=selected)
rad1.grid(column=0, row=0)
rad2.grid(column=1, row=0)</code>

A ScrolledText widget provides a multi‑line text area; its size is set with width and height , and text can be inserted or deleted using insert and delete .

<code>from tkinter import scrolledtext
txt = scrolledtext.ScrolledText(window, width=40, height=10)
txt.grid(column=0, row=0)
txt.insert(INSERT, "Text goes here")
txt.delete(1.0, END)</code>

Message boxes are shown via messagebox.showinfo inside a button callback.

<code>from tkinter import messagebox
def clicked():
    messagebox.showinfo("Message title", "Message content")
btn = Button(window, text="Click here", command=clicked)
btn.grid(column=0, row=0)</code>

File dialogs allow users to select files or directories using filedialog.askopenfilename , askopenfilenames , or askdirectory , optionally with initialdir and filetypes arguments.

<code>from tkinter import filedialog
file = filedialog.askopenfilename()
files = filedialog.askopenfilenames()
dir = filedialog.askdirectory()
</code>

Progress bars from tkinter.ttk are created with Progressbar , configured via the value option, and styled using a ttk.Style object.

<code>from tkinter.ttk import Progressbar, Style
style = Style()
style.theme_use('default')
style.configure('black.Horizontal.TProgressbar', background='black')
bar = Progressbar(window, length=200, style='black.Horizontal.TProgressbar')
bar['value'] = 70
bar.grid(column=0, row=0)
</code>

Spinboxes provide numeric input with a defined range ( from_ and to ) or a set of specific values, and can be linked to a variable for default values.

<code>spin = Spinbox(window, from_=0, to=100, width=5)
spin.grid(column=0, row=0)
var = IntVar()
var.set(36)
spin = Spinbox(window, from_=0, to=100, width=5, textvariable=var)
</code>

All examples are combined into complete scripts that create a functional GUI window with the demonstrated widgets and interactions.