I want to set variables when starting my Tornado webserver, so I tried to override initialize on my RequestHandler class. But apparently, initialize is launched each time a request is made, according to the following code and its output:
#!/usr/bin/env python3
# -*- coding: UTF-8 -*-
import tornado.web
class MainHandler(tornado.web.RequestHandler):
def initialize(self):
print("Launching initialization...")
def get(self):
print("Get: {}{}".format(self.request.host, self.request.uri))
app = tornado.web.Application([=
(r"/.*", MainHandler)
])
def runserver():
import tornado.ioloop
app.listen(8080)
tornado.ioloop.IOLoop.instance().start()
if __name__ == "__main__":
runserver()
stdout:
~ ➤ ./redirector.py
Launching initialization...
Get: 127.0.0.1:8080/
Launching initialization...
Get: 127.0.0.1:8080/favicon.ico
Launching initialization...
Get: 127.0.0.1:8080/favicon.ico
Launching initialization...
Get: 127.0.0.1:8080/
This behavior is the complete contrary to what is written in the doc:
Hook for subclass initialization.
(Meaning it is called at the end of __init__)
So, does anybody know how to do what I want to ?
Thanks in advance.
It's not contrary to the doc; have a look at the Structure of a Tornado app section. A RequestHandler object is created for each request.
If you want code to be executed when the app is started only, subclass the Application class and override __init__, or just put it in your runserver function.
Related
import configparser
from tkinter import *
from tkinter import filedialog,messagebox
from tkinter.filedialog import asksaveasfile
from customtkinter import *
import os
import time
import wikipedia
config=configparser.ConfigParser()
config.read("config.ini")
def change_config():
messagebox.showinfo("Information","App is going to restart in few seconds")
print(mode.get())
print(color.get())
global location
config.set("THEME","mode",str(mode.get()))
config.set("VOICE","voice",str(gender.get()))
if color.get() =="pink":
location="C:/Users/DELL/Documents/python programs/notepad/custom_theme.json"
config.set("THEME","color",location)
else :
config.set("THEME","color",color.get())
with open("config.ini","w") as configfile:
config.write(configfile)
restart()
def main():
global root,label,frame1,config_color,config_mode,config_gender
root=CTk()
root.geometry("700x600")
root.resizable(0,0)
root.title("Notepad")
frame1=CTkFrame(root,width=150,height=580)
frame1.pack_propagate(False)
frame1.place(x=10,y=10)
config_color=config.get("THEME","color")
config_mode=config.get("THEME","mode")
config_gender=config.get("VOICE","voice")
set_appearance_mode(config_mode)
set_default_color_theme(config_color)
label=CTkLabel(root,text="File",width=520,height=40,font=("Algerian",30))
label.place(x=170,y=10)
global S
global text_area
text_area=CTkTextbox(root,height=580,width=520,)
text_area.place(x=170,y=60)
global button,commands,button_text
button_text="Settings"
commands=settings
button=CTkButton(frame1,text=button_text,command=settings)
button.pack(padx=10,pady=10)
root.mainloop()
def settings():
global submit,mode,color,config_color,config_mode,gender
window=CTkToplevel(root)
window.title("Settings")
window.geometry("200x300")
label1=CTkLabel(window,text="Mode").pack(pady=5)
mode=CTkOptionMenu(window,values=["light","dark"])
mode.pack(pady=5,padx=5,anchor=CENTER)
label2=CTkLabel(window,text="Color").pack(pady=5)
color=CTkOptionMenu(window,values=["pink","blue","green","dark-blue"])
color.pack(pady=5)
label3=CTkLabel(window,text="speech-gender").pack(pady=5)
gender=CTkOptionMenu(window,values=["male","female"])
gender.pack(pady=5)
submit=CTkButton(window,text="Submit",command=change_config)
submit.pack(pady=20)
window.mainloop()
if __name__=="__main__":
def restart():
time.sleep(5)
root.destroy()
main()
main()
I want to create a notepad , where we can change themes and colors.
I have made config.ini file where i save the current mode, color and the voice type for the notepad ( voicetype is for text-to-speech functionality that i have added here ) becuase while using customtkinter we can set default color theme and cannot change it once initialized in a program.
The program now save the selected preferences in config.ini file and grab it when run again.
I want the program to run again itself without having the need to explicitly run it again.
Though program is running i am still getting this error at backend:
invalid command name "2912423726080check_dpi_scaling"
while executing
"2912423726080check_dpi_scaling"
("after" script)
invalid command name "2912423728512update"
while executing
"2912423728512update"
("after" script)
invalid command name "2912423728448<lambda>"
while executing
"2912423728448<lambda>"
("after" script)
I want to know what this error means so that the users might not face problem in future while using this app.
Thanks in advance for helping.
I have the following problem.
I'd like to run tests on the local flask server before deploying to production. I use pytest for that. My conftest.py looks like that for the moment:
import pytest
from toolbox import Toolbox
import subprocess
def pytest_addoption(parser):
"""Add option to pass --testenv=local to pytest cli command"""
parser.addoption(
"--testenv", action="store", default="exodemo", help="my option: type1 or type2"
)
#pytest.fixture(scope="module")
def testenv(request):
return request.config.getoption("--testenv")
#pytest.fixture(scope="module")
def testurl(testenv):
if testenv == 'local':
return 'http://localhost:5000/'
else:
return 'https://api.domain.com/'
This allows me to test the production api by typing the command pytest and to test a local flask server by typing pytest --testenv=local
This code WORKS flawlessly.
My problem is that I have to manually instantiate the local flask server from the terminal each time I want to test locally like this:
source ../pypyenv/bin/activate
python ../app.py
Now I wanted to add a fixture that initiates a terminal in the background at the beginning of the tests and closes the server down after having finished testing. After a lot of research and testing, I still cannot get it to work. This is the line I added to the conftest.py:
#pytest.fixture(scope="module", autouse=True)
def spinup(testenv):
if testenv == 'local':
cmd = ['../pypyenv/bin/python', '../app.py']
p = subprocess.Popen(cmd, shell=True)
yield
p.terminate()
else:
pass
The errors I get are from the requests package that says that there is no connection/ refused.
E requests.exceptions.ConnectionError:
HTTPConnectionPool(host='localhost', port=5000): Max retries exceeded
with url: /login (Caused by
NewConnectionError(': Failed to establish a new connection:
[Errno 111] Connection refused',))
/usr/lib/python3/dist-packages/requests/adapters.py:437:
ConnectionError
This means for me that the flask server under app.py is not online. Any suggestions? I am open to more elegant alternatives
For local testing the Flask test_client is a more elegant solution. See the docs on Testing. You can create a fixture for the test_client and create test requests with that:
#pytest.fixture
def app():
app = create_app()
yield app
# teardown here
#pytest.fixture
def client(app):
return app.test_client()
And use it like this:
def test_can_login(client):
response = client.post('/login', data={username='username', password='password'})
assert response.status_code == 200
If the only problem are the manual steps, maybe consider a bash script that does your manual setup for you and after that executes pytest.
I am using the following for this purpose so that testing configuration is also preserved in the test server
#pytest.fixture(scope="session")
def app():
db_fd, db_path = tempfile.mkstemp()
app = create_app({
'TESTING': True,
'DATABASE': db_path
})
yield app
os.close(db_fd)
os.unlink(db_path)
from flask import request
def shutdown_server():
func = request.environ.get('werkzeug.server.shutdown')
if func is None:
raise RuntimeError('Not running with the Werkzeug Server')
func()
#pytest.fixture
def server(app):
#app.route('/shutdown',methods=('POST',))
def shutdown():
shutdown_server()
return 'Shutting down server ...'
import threading
t = threading.Thread(target=app.run)
yield t.start()
import requests
requests.post('http://localhost:5000/shutdown')
References
https://flask.palletsprojects.com/en/1.1.x/tutorial/tests/
How do I terminate a flask app that's running as a service?
How to stop flask application without using ctrl-c
With a bash script (thanks #ekuusela) I now finally succeeded in what I wanted.
I added a fixture that calls the bashscript spinserver.sh in a new terminal window. This works in ubuntu, the command is different in different environments (see Execute terminal command from python in new terminal window? for other environments).
#pytest.fixture(scope="session", autouse=True)
def client(testenv):
if testenv != 'local':
pass
else:
p = subprocess.Popen(['gnome-terminal', '-x', './spinserver.sh'])
time.sleep(3)
yield
Here the very simple bashscript
#!/bin/bash
cd ..
source pypyenv/bin/activate
python app.py
The sleep command is necessary because the server takes some time to
initialize.
Don't forget to make your bash script executable (chmod
u+x spinserver.sh)
I tried to do a teardown after yield, but p.kill does not really
close the window. This is acceptable for me as it does not matter
if I have to manually close a terminal window & I can even see
flask debugging if necessary
This is my code:
import _thread
import http.server
import socketserver
def func():
PORT = 8002
Handler = http.server.SimpleHTTPRequestHandler
httpd = socketserver.TCPServer(("", PORT),Handler)
_thread.start_new_thread(httpd.serve_forever())
func()
I want to run this on the background, Is it possible.The above code is not working as expected it is working on the foreground.How can I make it on the Background?
I want this to test my downloader written in python.
.....
r=requests.get('http://localhost:8002/file.dat',stream=True)
with open('file.dat','wb')as f:
for chunk in r.iter_content(chunk_size=(1*1024*1024):
f.write(chunk)
......
And I can't use more than one processor because I am writing this code in pythonista in iOS which does not support the use of more than one process but supports the use of multithreading
My small aiohttp1 app was working fine until I have started preparing for deploying to Heroku servers. Heroku forces me to use gunicorn. It wasn't working with aiohttp1 (some strange errors), and after a small migration aiohttp2 I have started app with
gunicorn app:application --worker-class aiohttp.GunicornUVLoopWebWorker
command and I works, until I have requested view that calls class' async method with
with async_timeout.timeout(self.timeout):
res = await self.method()
code inside and it raises RuntimeError: Timeout context manager should be used inside a task error.
The only thing that changed until last successful version: the fact that I'm using gunicorn. I'm using Python 3.5.2 and uvloop 0.8.0 and gunicorn 19.7.1.
What is wrong and how can I fix this?
UPD
The problem is that I have LOOP variable that store newly created event loop. This variable definition is in setting.py file, so before aiohttp.web.Application creating, code below gets evaluated:
LOOP = uvloop.new_event_loop()
asyncio.set_evet_loop(LOOP)
and this causes error when using async_timeout.timeout context manager.
Code to reproduce the error:
# test.py
from aiohttp import web
import uvloop
import asyncio
import async_timeout
asyncio.set_event_loop(uvloop.new_event_loop())
class A:
async def am(self):
with async_timeout.timeout(timeout=1):
await asyncio.sleep(0.5)
class B:
a = A()
async def bm(self):
await self.a.am()
b = B()
async def hello(request):
await b.bm()
return web.Response(text="Hello, world")
app = web.Application()
app.router.add_get('/', hello)
if __name__ == '__main__':
web.run_app(app, port=5000, host='localhost')
and just run gunicorn test:app --worker-class aiohttp.GunicornUVLoopWebWorker (same error when using GunicornWebWorker with uvloop event loop, or any other combination).
solution
I have fixed this by calling asyncio.get_event_loop when I need to use event loop.
I am spinning up a Waitress web server in a background thread to run functional tests. How it is possible to clean up and quit waitress at the end of test run in clean(ish) manner? The public waitress API gives only one way entry point which expects KeyboardInterrupt as the quit signal.
Currently I just run the server in a daemon thread and all new web servers are pending clean up until the test runner quits.
My test web server code:
"""py.test fixtures for spinning up a WSGI server for functional test run."""
import threading
import time
from pyramid.router import Router
from waitress import serve
from urllib.parse import urlparse
import pytest
from backports import typing
#: The URL where WSGI server is run from where Selenium browser loads the pages
HOST_BASE = "http://localhost:8521"
class ServerThread(threading.Thread):
"""Run WSGI server on a background thread.
This thread starts a web server for a given WSGI application. Then the Selenium WebDriver can connect to this web server, like to any web server, for running functional tests.
"""
def __init__(self, app:Router, hostbase:str=HOST_BASE):
threading.Thread.__init__(self)
self.app = app
self.srv = None
self.daemon = True
self.hostbase = hostbase
def run(self):
"""Start WSGI server on a background to listen to incoming."""
parts = urlparse(self.hostbase)
domain, port = parts.netloc.split(":")
try:
# TODO: replace this with create_server call, so we can quit this later
serve(self.app, host='127.0.0.1', port=int(port))
except Exception as e:
# We are a background thread so we have problems to interrupt tests in the case of error. Try spit out something to the console.
import traceback
traceback.print_exc()
def quit(self):
"""Stop test webserver."""
# waitress has no quit
# if self.srv:
# self.srv.shutdown()
Webtest provides a WSGI server named StopableWSGIServer that gets started in a separate thread, and then can be shutdown() when you are done running your tests.
Check out: https://docs.pylonsproject.org/projects/webtest/en/latest/api.html#module-webtest.http
According to the documentation it was specifically built for use with casperjs or selenium.