main.py
import flet as ft

def main(page: ft.Page):
    """縦横スクロール付きDataTable
    縦スクロール(コンテナのheight必須):
        ft.Container(
            content=ft.ListView(
                ft.DataTable()
            )
            height=CONTAINER_HEIGHT
            width=CONTAINER_WIDTH 
        )
    横スクロール(scroll="auto" or "always"必須):
      ft.Row(scroll="auto")
      ウィンドウ幅 < コンテンツ幅
    """
    CONTAINER_HEIGHT = 500
    CONTAINER_WIDTH = 450
    page.window_width = 400

    dt_cols = []
    for col in ["ID", "Name", "Age"]:
        dt_cols.append(ft.DataColumn(ft.Text(col))) 

    dt_rows = []
    for row in [(x, f"Test{x}", x) for x in range(1, 101)]:
        cells = []
        for cell in row:
            cells.append(ft.DataCell(ft.Text(cell)))
        dt_rows.append(ft.DataRow(cells))

    dt = ft.DataTable(
        columns=dt_cols,
        rows=dt_rows
    )

    lv = ft.ListView([dt], expand=1, spacing=10, padding=20)

    page.add(
        ft.Row(
            [
                ft.Container(
                    content=lv,
                    border=ft.border.all(1),
                    height=CONTAINER_HEIGHT,
                    width=CONTAINER_WIDTH,
                ),
            ],
            scroll="auto",
        )
    )

ft.app(target=main)