Here is how to build a GUI with FreeSimpleGUI in Python.

Explanation:

1. We import FreeSimpleGUI as sg for convenience.
2. The layout list defines the window's content. In this case, it has a row with a text element and a button.
3. The sg.Window function creates the window with the specified title ("My First GUI") and the layout.
4. The while True loop keeps the window open until the user closes it.
5. window.read() pauses the program and waits for user interaction (closing the window or clicking the button). It returns a tuple containing the event name (e.g., button click, window closed) and the current values of all input elements (empty in this case).
6. The if statements check for the event type:
   • sg.WIN_CLOSED: The user closed the window, so we break out of the loop.
   • "Click Me": The button was clicked, and we print a message to the console.
7. Finally, window.close() closes the window after the loop exits.

Running the Script:

Save the code as a Python file (e.g., my_window.py) and run it from the terminal:

python my_window.py

This will display a window with the text "Hello, World!" and a button labeled "Click Me." Clicking the button will print "Button clicked!" to the console.

Adding Input Fields:

Let's modify the example to include an input field where users can enter their name and a button to greet them:

import FreeSimpleGUI as sg
layout = [
  [sg.Text("Enter your name:")],
  [sg.InputText(key="name")],
  [sg.Button("Greet Me")]
]
window = sg.Window("Greeting App", layout)
while True:
  event, values = window.read()
  if event == sg.WIN_CLOSED:
    break
  elif event == "Greet Me":
    name = values["name"]
    print(f"Hello, {name}!")
window.close()

Here, we've added an sg.InputText element with the key "name" to capture user input. In the event loop, we retrieve the entered name from the "values" dictionary and use it to create a personalized greeting message.

Customizing the Look and Feel:

FreeSimpleGUI allows some basic customization options for the window and elements. Here are a couple of examples:

• Window Size: Pass a tuple to the size argument of sg.Window to set the width and height in pixels (e.g., sg.Window("Window", layout, size=(600, 400))).
• Font Size: Use the font argument within element creation functions to set the font and size (e.g., sg.Text("Text", font=("Arial", 12))).