Text input with value sometimes reverts input

Summary

When using an st.text_input and setting the value= argument, sometimes the user input is reset to the previous input.

Steps to reproduce

Run this streamlit script that reads a string from a file, sets it as value of a text input, and saves the returned value of the input to the file again:

import streamlit as st

try:
    with open('value.txt', 'r') as file:
        before = file.read()
except OSError:
    before = 'a'

after = st.text_input('Input:', value=before)
st.write('Before:', before, 'After:', after)

with open('value.txt', 'w') as file:
    file.write(after)

Expected behavior:

a + Enter = Before: a After: a Input: a b + Enter = Before: a After: b Input: b c + Enter = Before: b After: c Input: c

Actual behavior:

a + Enter = Before: a After: a Input: a b + Enter = Before: a After: b Input: b c + Enter = Before: b After: b Input: b <<< RESET

This happens on every second input, whenever before and after values are not the same. It works as expected if you use the input without a value:

after = st.text_input('Input:')

Debug info

• Streamlit version: 0.50.2
• Python version: 3.7.4

Might be related to https://github.com/streamlit/streamlit/issues/218

[ShaharMynd]

@nthmost as said, this is still a problem.

I face the same issue, after creating text_input with a unique key, Sometimes, Usually on the second update The result from the input is the previous value.

[nthmost]

Still a problem. I just reproduced this error using the OP code.

Additionally, setting a key on the text_input doesn’t help.