Python - How to run multiple flask apps from same

Question

I have one flask application script as given below :

from flask import Flask
app = Flask(__name__)

@app.route("/<string:job_id>")
def main(job_id):
    return "Welcome!. This is Flask Test Part 1"

if __name__ == "__main__":
    job_id = 1234
    app.run(host= '0.0.0.0')

I have another flask application script as below :

from flask import Flask
app = Flask(__name__)

@app.route("/<string:ID>")
def main(ID):
    return "Welcome!. This is Flask Test Part 2"

if __name__ == "__main__":
    ID = 5678
    app.run(host= '0.0.0.0')

The only difference between both the scripts is the argument name and its value. Now my question is assume that I am executing the first script. So I will get something like

* Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)

When I execute http://127.0.0.1:5000/1234 in my browser I am able to see

"Welcome!. This is Flask Test Part 1"

Now with this server active, I am executing the second script. So again I get

* Running on http://0.0.0.0:5000/ (Press CTRL+C to quit)

But when I execute http://127.0.0.1:5000/5678 in my browser I am able to see

"Welcome!. This is Flask Test Part 1"

instead of

"Welcome!. This is Flask Test Part 2"

I don't understand where I am doing mistake. Any inputs or alterations will be helpful

Answer 1

Flask development server by default listen on port 5000. So when you run a Flask app without port number it will run on 5000.

You can run number of Flask app on the same machine but with different port number. Lets say your scripts names are script1.py and script2.py:

$ export FLASK_APP=script1.py
$ flask run --host 0.0.0.0 --port 5000

Open up a new terminal

$ export FLASK_APP=script2.py
$ flask run --host 0.0.0.0 --port 5001