app.py

import streamlit as st
import pexpect
import time

if 'child' not in st.session_state:
    st.session_state['child'] = pexpect.spawn("python danse_macabre.py", encoding='utf-8', timeout=None)

child = st.session_state['child']

if 'messages' not in st.session_state:
    st.session_state['messages'] = []

# creating a single-element container
placeholder = st.empty()

user_input = st.text_input("What do you do or say ?")
if user_input :
    child.sendline(str(user_input))
    user_input=""

while True:
    with placeholder.container():
        #Let's see if there's a new message
        try :
            #If there's no exception it means yes
            line = child.read_nonblocking(size=1000, timeout=0)
            #Let's add it to the list of messages
            st.session_state['messages'].append(line)
        except:
            pass

        # Display the list of messages in the placeholder
        for msg in st.session_state['messages']:
            st.write(msg)
    #Try again in X sec
    time.sleep(0.5)