IndentationError: expected an indented block [Python] - python

I got this very simple Python code, but somehow I always get an error:
IndentationError: expected an indented block
I checked all tabs and spaces twice and I can not find the mistake.
Can someone please give me a hint?
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello World!\n'
if __name__ == '__main__':
app.run(debug=True, host='0.0.0.0')

May be it is due the editor or improper indentation.
Your code is perfectly running in my pc but I would suggest to run the below code
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello World!'
if __name__ == '__main__':
app.debug = True
app.run(port=8080)

For me worked this in the docker example.
from flask import Flask
app = Flask(__name__)
#app.route('/')
def hello_world():
return 'Hello World!'
if __name__ == '__main__':
app.debug = True
app.run(host='0.0.0.0')

Related

Flask is not providing a URL

I am a new programmer and I am trying to connect my bot to flask to create a URL for discord.
when I run it, it doesn't do it. Am I missing a line here because it is not coming up with an error but it will not run either.
from threading import Thread
app = Flask ('__code__')
#app.route('/')
def home():
return "Hello. I am alive!"
app.run(host='0.0.0.0',port=5000)
def keep_alive():
t = Thread(target=run)
t.start()
if __name__ == '__code__':
app.run()```
Can someone point me in the right direction? I normally work on python 3.
Thank you
Try running the app when checking the name of your code, not in home() function:
from flask import Flask
from threading import Thread
app = Flask ('__code__')
#app.route('/')
def home():
return "Hello. I am alive!"
def keep_alive():
t = Thread(target=run)
t.start()
if __name__ == '__code__':
app.run(host='0.0.0.0',port=5000)

Python Flask call index function without refresh page?

from flask import Flask,render_template
app = Flask(__name__)
#app.route('/')
def index():
print('hello')
return render_template('index.html')
if __name__ == '__main__':
app.run(debug=True)
the index function is run whenever there is a request, so it is pressed on the "hello" console screen every time the site is refreshed or entered. So how can I always print "hello" in real time without refreshing this page?
What do you mean, saying "always"?
When you run flask app it starts in main thread, so if you want to make some worker(who for example prints your hello word), just create a new thread, and put in there.
Example:
from flask import Flask,render_template
import threading,time
app = Flask(__name__)
#app.route('/')
def index():
return render_template('index.html')
def start_new_thread():
def worker(arg1,arg2):
while(True):
print("hello")
time.sleep(2)
thread = threading.Thread(target=worker,args=("your argument","sencond one"))
thread.start();
if __name__ == '__main__':
start_new_thread()
app.run(debug=True)
print("OK")#never be printed because app.run starts in main thread

waitress command line returning "Malformed Application" when deploying flask web app

I'm attempting to deploy a simple web app, and I'm using command line waitress-serve --call command. But every time, the command immediately returns 1. Malformed application 'name_of_project_here'.
Here's my flask web app in python:
from flask import Flask, render_template
app = Flask(__name__)
#app.route('/')
def index():
return render_template('base.html')
if __name__ == '__main__':
app.run(debug = True)
and the command I run is just
waitress-serve --call "name_of_project"
I did try looking through the documentation, and I found where the error occurs, but couldn't find an explanation of why it's occurring. What does malformed application mean?
Minimal working example:
If you put code in file main.py
from flask import Flask
def create_app():
app = Flask(__name__)
#app.route('/')
def index():
return "Hello World!"
return app
if __name__ == '__main__':
app = create_app()
app.run()
then you can run it as
waitress-serve --call "main:create_app"
So "name_of_project" has to be "filename:function_name" which creates Flask() instance.
It can't be any text. And if you forget : then you may see "Malformed application"
when defining your appname and the function that initialize your app with : dont put them into quotes('')

Unable to see any message in website using flask

In my local host, I'm unable to see any message. I am using jupyter notebook.
from flask import Flask
app = Flask(__name__)
#app.route("/")
def hello():
return "Hello World"
if __name__ == "__main__":
app.debug = True
app.run(host='0.0.0.0',port=5005)

Python Output in localhost even after defining app route to '/hello'

Here's the code:-
from flask import Flask
app= Flask(__name__)
#app.route('/hello')
def hello_world() :
return 'hello World'
app.add_url_rule('/','hello','hello_world')
if __name__== '__main__':
app.run(debug=True)
Please see if u can find an error, please type the correct code in the answer
Please see documentation for add_url_rule, required method name instead you will give in string format for 'hello_world', hello_world
from flask import Flask
app= Flask(__name__)
#app.route('/hello')
def hello_world():
return 'hello World'
app.add_url_rule('/','hello', hello_world)
if __name__== '__main__':
app.run(debug=True)

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