Today, I'd like to share a story about interactive development Web app Super simple tool . Can't HTML,CSS,JAVASCRIPT It's okay. .

Interactive Web app Very practical , For example, make a questionnaire page 、 A voting system 、 An information collection form , Upload files and so on , Because web pages are visual , Therefore, it can also be used as a picture interface application without server .

If you have such development needs , The use Python It's so simple .

With the help of PyWebIO（pip install pywebio）, You can enter the information of the web page in minutes , You can see the following dynamic diagram ：

The page above , Just use this 6 Line code ：

from pywebio.input import *
input("This is a simple text input")
select("This is a drop down menu", ['Option1', 'Option2'])
checkbox("Multiple Choices!", options=["a",'b','c','d'])
radio("Select any one", options=['1', '2', '3'])
textarea('Text Area', rows=3, placeholder='Multiple line text input')

It's also very simple to make the web page output the information you want , The code is as follows , The function has been annotated , It's easy for you to understand ：

from pywebio.output import *
from pywebio import session
# Display plain text on the web page
put_text("Hello friend!")
# Display table on Web page
put_table([
['Object', 'Unit'],
['A', '55'],
['B', '73'],
])
# The web page shows MarkDown
put_markdown('~~PyWebIO~~')
# The web page displays a link to download the file
put_file('output_file.txt', b'You can put anything here')
# Show pictures on Web pages
put_image(open('python_logo.png', 'rb').read())
# A pop-up window appears on the web page
popup('popup title', 'popup text content')
# Keep the reply open , Otherwise, the program exits after the page is displayed
session.hold()

The effect of the operation is as follows ：

above , A few lines of code implement a with input and output Web application , Isn't that amazing ？

Build browser based GUI Program

PyWebIO It provides a series of command interactive functions to obtain user input and output on the browser , Turn the browser into a “ Rich text terminal ”, Can be used to build simple Web Application or browser based GUI application .

For example, calculation BMI Exponential script ：

from pywebio import start_server
from pywebio.input import input, FLOAT
from pywebio.output import put_text
def bmi():
height = input(" Please enter your height (cm)：", type=FLOAT)
weight = input(" Please enter your weight (kg)：", type=FLOAT)
BMI = weight / (height / 100) ** 2
top_status = [(14.9, ' Extremely thin '), (18.4, ' Thin '),
(22.9, ' normal '), (27.5, ' overweight '),
(40.0, ' obesity '), (float('inf'), ' Very fat ')]
for top, status in top_status:
if BMI <= top:
put_text(' Yours BMI value : %.1f, Physical condition ：%s' % (BMI, status))
break
if __name__ == '__main__':
start_server(bmi, port=80)

effect ：

More examples ：

basic demo

• The chat room : Chat with everyone currently online ( Less than 90 Line code implementation )
• Markdown Real-time Preview : Online that can be previewed in real time Markdown Editor ( Less than 40 Line code implementation )
• Online Gobang game : A Gobang game in which many people cooperate against each other ( Less than 100 Line code implementation )
• Input presentation : demonstration PyWebIO Usage of input module
• Output Demo : demonstration PyWebIO Usage of output module

Data visualization demo

PyWebIO It also supports data visualization using third-party libraries

• Use bokeh Data visualization
• Use plotly Data visualization
• Use pyecharts Create based on Echarts The chart
• Use pyg2plot Create based on G2Plot The chart
• Use cutecharts.py Create cartoon style charts

Data visualization rendering ：

Integration with existing frameworks

PyWebIO It can also be easily integrated into existing Web service , So you don't have to write HTML and JS Code , You can build applications with good usability . At present, we support Flask、Django、Tornado、aiohttp、FastAPI Framework for the integration .

For example, with Tornado Application Integration ：

import tornado.ioloop
import tornado.web
from pywebio.platform.tornado import webio_handler
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello, world")
if __name__ == "__main__":
application = tornado.web.Application([
(r"/", MainHandler),
(r"/bmi", webio_handler(bmi)), # bmi Is calculated above BMI Exponential function
])
application.listen(port=80, address='localhost')
tornado.ioloop.IOLoop.current().start()

And Django Integrate ：

# urls.py
from django.urls import path
from pywebio.platform.django import webio_view
# `task_func` is PyWebIO task function
webio_view_func = webio_view(task_func)
urlpatterns = [
path(r"tool", webio_view_func),
]

Last

PyWebIO Get input using synchronization rather than callback based methods , Coding logic is more natural , Non declarative layout , The layout is simple and efficient , The code is less intrusive , The old script code can be transformed into Web service , It can also be integrated into the existing mainstream Web frame . Both thread based execution model and co process based execution model are supported , Support data visualization in combination with third-party libraries

In a word ,PyWebIO Let interactive Web Development becomes easier , It is especially suitable for developing simple GUI Program and data visualization .