There is a lot docs for FLET Filepicker.
I think this code can help you:
import flet
from flet import (Page, FilePicker, Text,
ElevatedButton, Row, Column, FilePickerResultEvent)
def main(page: Page):
# 2) CREATE THE EVENT FOR FILEPICKER (TO OPEN THE FILEPICKER DIR WINDOW)
def select_file(e: FilePickerResultEvent):
page.add(filepicker)
filepicker.pick_files("Select file...")
# 3) CREATE THE FUNCTION OF EVENT
def return_file(e: FilePickerResultEvent):
file_path.value = e.files[0].path
file_path.update()
row_filepicker = Row(vertical_alignment="center")
file_path = Text(value="Selected file path", expand=1)
# 1) CREATE A FILEPICKER:
filepicker = FilePicker(on_result=return_file)
row_filepicker.controls.append(
ElevatedButton(
text="Select file...", on_click=select_file))
# ADD THE PATH (if you will select it)
row_filepicker.controls.append(
file_path)
page.add(row_filepicker)
if __name__ == '__main__':
flet.app(target=main)