app.py

import time
import pandas as pd
import gradio as gr

with gr.Blocks() as blocks:

    def update_first_df(df):
        print('update first df')
        time.sleep(1)
        return df + 1
    
    def update_second_df(df):
        print('update second df')
        time.sleep(1)
        return df + 1

    first_df = gr.Dataframe(pd.DataFrame({'A': [1], 'B': [2]}))
    second_df = gr.Dataframe(pd.DataFrame({'A': [3], 'B': [4]}))

    first_df.select(fn=update_second_df, inputs=[second_df], outputs=[second_df])
    second_df.select(fn=update_first_df, inputs=[first_df], outputs=[first_df])


blocks.launch()