I am trying to understand how to update realtime data in streamlit app.Looping through the numbers 1 to 100, display the number along with number * 10. But streamlit always shows number as 1.
Steps to reproduce
Code snippet:
mport threading
import streamlit as st
import time
global val, multiply
def test_run():
global val, multiply
for x in range(1, 100):
val = x
multiply = val * 10
print(val)
time.sleep(1)
return val, multiply
threading.Thread(target=test_run).start()
# dashboard title
st.title("Stramlit Learning")
# creating a single-element container.
placeholder = st.empty()
with placeholder.container():
col1, col2 = st.columns(2)
col1.metric(label="Current Value", value=val)
col2.metric(label="Multiply by 10 ", value=multiply)
If applicable, please provide the steps we should take to reproduce the error or specified behavior.
You can use queue in this case to capture the values from data generator. You can then show the values in metric.
Here is a demo based from your code.
import threading
import streamlit as st
import time
import queue
q = queue.Queue()
def test_run():
for x in range(1, 100):
time.sleep(1)
val = x
multiply = val * 10
q.put((val, multiply))
is_exit_target_if_main_exits = True
threading.Thread(
target=test_run,
daemon=is_exit_target_if_main_exits).start()
# dashboard title
st.title("Streamlit Learning")
# creating a single-element container.
placeholder = st.empty()
# Exit loop if we will not receive data within timeoutsec.
timeoutsec = 30
# Simulate data from test_run() in placeholder.
while True:
try:
val, multiply = q.get(block=True, timeout=timeoutsec)
except queue.Empty:
break # exit loop
else:
with placeholder.container():
col1, col2 = st.columns(2)
col1.metric(label="Current Value", value=val)
col2.metric(label="Multiply by 10 ", value=multiply)
q.task_done()