Stream a generator, iterable, or stream-like sequence to the app.

st.write_stream iterates through the given sequences and writes all chunks to the app. String chunks will be written using a typewriter effect. Other data types will be written using st.write.

Function signature[source]

st.write_stream(stream)

Parameters

arg (Callable, Generator, Iterable, OpenAI Stream, or LangChain Stream)

The generator or iterable to stream.

Returns

(str or list)

The full response. If the streamed output only contains text, this is a string. Otherwise, this is a list of all the streamed objects. The return value is fully compatible as input for st.write.

Example

You can pass an OpenAI stream as shown in our tutorial, Build a basic LLM chat app. Alternatively, you can pass a generic generator function as input:

import time
import numpy as np
import pandas as pd
import streamlit as st

_LOREM_IPSUM = """
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor
incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.
"""


def stream_data():
    for word in _LOREM_IPSUM.split():
        yield word + " "
        time.sleep(0.02)

    yield pd.DataFrame(
        np.random.randn(5, 10),
        columns=["a", "b", "c", "d", "e", "f", "g", "h", "i", "j"],
    )

    for word in _LOREM_IPSUM.split():
        yield word + " "
        time.sleep(0.02)


if st.button("Stream data"):
    st.write_stream(stream_data)
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