Introduction

What is Flet?

Flet is a framework that allows building web, desktop and mobile applications in Python without prior experience in frontend development.

You build a UI for your program with Flet controls which which are based on Flutter by Google. Flet does not just "wrap" Flutter widgets, but adds its own "opinion" by combining smaller widgets, hiding complexities, implementing UI best-practices, applying reasonable defaults - all to ensure your apps look cool and professional without extra efforts.

Flet app example

Create a sample "Counter" app:

counter.py
import flet as ft

def main(page: ft.Page):
    page.title = "Flet counter example"
    page.vertical_alignment = ft.MainAxisAlignment.CENTER

    txt_number = ft.TextField(value="0", text_align=ft.TextAlign.RIGHT, width=100)

    def minus_click(e):
        txt_number.value = str(int(txt_number.value) - 1)
        page.update()

    def plus_click(e):
        txt_number.value = str(int(txt_number.value) + 1)
        page.update()

    page.add(
        ft.Row(
            [
                ft.IconButton(ft.icons.REMOVE, on_click=minus_click),
                txt_number,
                ft.IconButton(ft.icons.ADD, on_click=plus_click),
            ],
            alignment=ft.MainAxisAlignment.CENTER,
        )
    )

ft.app(main)