如何在Streamlit中选择任何Python小部件后停止重新加载页面

Question

目前，我有以下两个问题:

问题1

当我选择任何带有Streamlit的小部件时，页面总是重新加载。

如何复制:

1. 加载页面
2. 选择文件夹
3. 选择任意选项
4. 当前:页面重新加载

期望:停止重新加载页面

---

问题2

按钮Import source自动运行

如何复制:

1. 加载页面
2. 选择文件夹
3. 遵守标签
4. 当前:显示文本The button runs?

期望:不显示文本，只有点击按钮，功能才会运行。

---

Main.py:

import streamlit as st
import Views.DBImport as dbImport
import Controllers.MongoDBConnection as con
import Processor as processor
import Scraper as scraper
import os
import tkinter as tk
from tkinter import filedialog
import numpy as np
st.title('Test System')
def ProcessFile(dirName):
fileList = []
dirlist = []
fileName = None
for root, dirs, files in os.walk(dirName):
for file in files:
fileList.append([file])
dirlist.append([dirPath + '/' + file])
if not fileName:
fileName = file.split(".")[0]
if not fileList or not dirlist:
st.write('Cannot read source folder!')
st.stop()
return np.concatenate((fileList, dirlist), axis=1), fileName
def ImportData(title, totalRecords, options, sampleRate, times):
title = title + sampleRate
return title
def ReadProperty(fileName, dirName):
ecgProperty = processor.GetSourceProperty(fileName, dirName)
# st.write(ecgProperty.channel)
if not ecgProperty.channel:
st.write('Cannot read source property!')
st.stop()
col1, col2, col3 = st.columns(3)
with col1:
title = st.text_input('Source name', 'Test')
st.text('Total records')
totalRecords = st.text(str(ecgProperty.record))
with col2:
options = st.multiselect(
'Channel(s)',
['I', 'II', 'III',
'aVR', 'aVL', 'aVF',
'V1', 'V2', 'V3',
'V4', 'V5', 'V6'])
st.text('Total channels')
st.text(str(len(options)))
with col3:
sampleRate = st.slider('Sample rate', 0, 10000,
ecgProperty.sample_rate)
st.text('Time(s)')
times = st.text(str(ecgProperty.time))
if st.button('Import source'):
result = ImportData(title, totalRecords, options, sampleRate, times)
st.write('result: %s' % result)
else:
st.write('The button runs?')
# Set up tkinter
root = tk.Tk()
root.withdraw()
# Make folder picker dialog appear on top of other windows
root.wm_attributes('-topmost', 1)
# Folder picker button
st.text('Please select a folder:')
clicked = st.button('Folder Picker')
if clicked:
dirPath = filedialog.askdirectory(master=root)
dirName = st.text_input('Selected folder:', dirPath)
# Process to get the list of files when selecting the folder
fileList, fileName = ProcessFile(dirName)
# Read ECG properties when user selects a source
ReadProperty(fileName, dirName)

Answer 1

这两个问题有不同的解决办法。

问题1

您可能需要的是st.form:

with st.form(key="form"):
files = st.file_uploader("Files", accept_multiple_files=True)
submit_button = st.form_submit_button(label="Submit choice")
if submit_button:
if files:
st.markdown("You chose the files {}".format(", ".join([f.name for f in files])))
else:
st.markdown("You did not choose any file but clicked on 'Submit choice' anyway")
else:
st.markdown("You did not click on submit button.")

st.form确保你可以选择任何你想要的，没有小部件将被重新加载，直到你点击通过st.form_submit_button(label="Submit choice")调用的按钮。它适用于任何输入:

name = st.text_input("Your name")
selected_cities = st.multiselect("Cities", ["Paris", "Milan", "Tokyo"])
submit_button = st.form_submit_button(label="Submit choice")
if submit_button:
st.markdown("{} wants to live in the following cities: {}".format(name, ",".join(selected_cities)))

问题2

你需要的是st.stop。它告诉Streamlit在你的应用程序执行时停止。

if st.button('Import source'):
result = ImportData(title, totalRecords, options, sampleRate, times)
st.write("result: %s" % result)
else: 
st.write("You did not click on 'Import source', we stop here.")
st.stop()
st.write("This is never run, it is just after a stop..")
st.write("This is run because you clicked on 'Import source'")