Flask CORS based API hosted on Heroku

(base) C:\Users\Ashish Jain\OneDrive\Desktop\murmuring-ridge-75281>type *

Procfile

web: python TestService.py

requirements.txt

flask
flask_restful
flask-cors

TestService.py

from flask import Flask, request
from flask_restful import Resource, Api
from flask_cors import CORS, cross_origin
import os

app = Flask(__name__)
cors = CORS(app)
app.config['CORS_HEADERS'] = 'Content-Type'

api = Api(app)

class Test(Resource):
    def get(self):
        result = "Hello World"
        return result

api.add_resource(Test, '/test') # URL Route

if __name__ == '__main__':
    port = int(os.environ.get('PORT', 5000))
    app.run(host='0.0.0.0', port=port)
    
-----------------------------------

Test.html

<script crossorigin="anonymous" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4="
    src="https://code.jquery.com/jquery-3.2.1.min.js"></script>

    
<script>
    function myclick() {
        $.get("https://murmuring-ridge-75281.herokuapp.com/test", function (data, status) {
            alert("Data: " + data + "\nStatus: " + status);
        });
    }
</script>

<button class="customBtn" onclick="myclick()">GET</button>

-----------------------------------

Error 1

(base) C:\Users\Ashish Jain\OneDrive\Desktop\gentle-garden-53110>git commit -m "#"
[master a4dd273] #
 1 file changed, 1 insertion(+)
 create mode 100644 Procfile

(base) C:\Users\Ashish Jain\OneDrive\Desktop\gentle-garden-53110>git push
Enumerating objects: 6, done.
Counting objects: 100% (6/6), done.
Delta compression using up to 4 threads
Compressing objects: 100% (4/4), done.
Writing objects: 100% (6/6), 722 bytes | 361.00 KiB/s, done.
Total 6 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Building on the Heroku-20 stack
remote: -----> Determining which buildpack to use for this app
remote:  !     No default language could be detected for this app.
remote:                         HINT: This occurs when Heroku cannot detect the buildpack to use for this application automatically.
remote:                         See https://devcenter.heroku.com/articles/buildpacks
remote:
remote:  !     Push failed
remote: Verifying deploy...
remote:
remote: !       Push rejected to gentle-garden-53110.
remote:
To https://git.heroku.com/gentle-garden-53110.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/gentle-garden-53110.git'

(base) C:\Users\Ashish Jain\OneDrive\Desktop\gentle-garden-53110>

(base) C:\Users\Ashish Jain\OneDrive\Desktop\gentle-garden-53110>heroku buildpacks:set heroku/python
Buildpack set. Next release on gentle-garden-53110 will use heroku/python.
Run git push heroku main to create a new release using this buildpack.

Error 2

(base) C:\Users\Ashish Jain\OneDrive\Desktop\gentle-garden-53110>git push
Enumerating objects: 6, done.
Counting objects: 100% (6/6), done.
Delta compression using up to 4 threads
Compressing objects: 100% (4/4), done.
Writing objects: 100% (6/6), 722 bytes | 361.00 KiB/s, done.
Total 6 (delta 0), reused 0 (delta 0), pack-reused 0
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Building on the Heroku-20 stack
remote: -----> Using buildpack: heroku/python
remote: -----> App not compatible with buildpack: https://buildpack-registry.s3.amazonaws.com/buildpacks/heroku/python.tgz
remote:        More info: https://devcenter.heroku.com/articles/buildpacks#detection-failure
remote:
remote:  !     Push failed
remote:  !
remote:  ! ## Warning - The same version of this code has already been built: a4dd27398a25f894326ca01b9651d867ee1a2c5f
remote:  !
remote:  ! We have detected that you have triggered a build from source code with version a4dd27398a25f894326ca01b9651d867ee1a2c5f
remote:  ! at least twice. One common cause of this behavior is attempting to deploy code from a different branch.
remote:  !
remote:  ! If you are developing on a branch and deploying via git you must run:
remote:  !
remote:  !     git push heroku <branchname>:main
remote:  !
remote:  ! This article goes into details on the behavior:
remote:  !   https://devcenter.heroku.com/articles/duplicate-build-version
remote:
remote: Verifying deploy...
remote:
remote: !       Push rejected to gentle-garden-53110.
remote:
To https://git.heroku.com/gentle-garden-53110.git
 ! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to 'https://git.heroku.com/gentle-garden-53110.git'

Error 3

(base) C:\Users\Ashish Jain\OneDrive\Desktop>heroku create --buildpack heroku/python
Creating app... !
 !    You've reached the app limit of 5 apps for unverified accounts. Delete some apps or add a credit card to verify your account.

How to set 'buildpack' at the time of creating project:

(base) C:\Users\Ashish Jain\OneDrive\Desktop>heroku create --buildpack heroku/python
Creating app... done, ⬢ murmuring-ridge-75281
Setting buildpack to heroku/python... done
https://murmuring-ridge-75281.herokuapp.com/ | https://git.heroku.com/murmuring-ridge-75281.git

-----------------------------------

README

![python](https://cloud.githubusercontent.com/assets/51578/13712821/b68a42ce-e793-11e5-96b0-d8eb978137ba.png)

# Heroku Buildpack: Python

[![CircleCI](https://circleci.com/gh/heroku/heroku-buildpack-python.svg?style=svg)](https://circleci.com/gh/heroku/heroku-buildpack-python)

This is the official [Heroku buildpack](https://devcenter.heroku.com/articles/buildpacks) for Python apps.

Recommended web frameworks include **Django** and **Flask**, among others. The recommended webserver is **Gunicorn**. There are no restrictions around what software can be used (as long as it's pip-installable). Web processes must bind to `$PORT`, and only the HTTP protocol is permitted for incoming connections.

See it in Action
----------------
```
$ ls
my-application		requirements.txt	runtime.txt

$ git push heroku main
Counting objects: 4, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (2/2), done.
Writing objects: 100% (4/4), 276 bytes | 276.00 KiB/s, done.
Total 4 (delta 0), reused 0 (delta 0)
remote: Compressing source files... done.
remote: Building source:
remote:
remote: -----> Python app detected
remote: -----> Installing python
remote: -----> Installing pip
remote: -----> Installing SQLite3
remote: -----> Installing requirements with pip
remote:        Collecting flask (from -r /tmp/build_c2c067ef79ff14c9bf1aed6796f9ed1f/requirements.txt (line 1))
remote:          Downloading ...
remote:        Installing collected packages: Werkzeug, click, MarkupSafe, Jinja2, itsdangerous, flask
remote:        Successfully installed Jinja2-2.10 MarkupSafe-1.1.0 Werkzeug-0.14.1 click-7.0 flask-1.0.2 itsdangerous-1.1.0
remote:
remote: -----> Discovering process types
remote:        Procfile declares types -> (none)
remote:
```

A `requirements.txt` must be present at the root of your application's repository to deploy.

To specify your python version, you also need a `runtime.txt` file - unless you are using the default Python runtime version.

Current default Python Runtime: Python 3.9.10

Alternatively, you can provide a `setup.py` file, or a `Pipfile`.
Using `pipenv` will generate `runtime.txt` at build time if one of the field `python_version` or `python_full_version` is specified in the `requires` section of your `Pipfile`.

Specify a Buildpack Version
---------------------------

You can specify the latest production release of this buildpack for upcoming builds of an existing application:

    $ heroku buildpacks:set heroku/python


Specify a Python Runtime
------------------------

Supported runtime options include:

- `python-3.10.2`
- `python-3.9.10`
- `python-3.8.12`
- `python-3.7.12`