Python flask flask不允许的方法所请求的URL不允许使用该方法

Question

I am using flask to deploy my deep learning model.

But when I am running my model I got this following error.

Method Not Allowed The method is not allowed for the requested URL

And when I activate debug mode I got this

flask.cli.NoAppException flask.cli.NoAppException: While importing "app", an ImportError was raised:

Traceback (most recent call last): File "c:\\users\\tab\\anaconda3\\lib\\site-packages\\flask\\cli.py", line 235, in locate_app import (module_name) File "C:\\Chatbot-Flask-Server-master\\Chatbot-Flask-Server-master\\app.py", line 3, in import tensorflow as tf ModuleNotFoundError: No module named 'tensorflow'

I had installed my tensorflow and the model can running well without flask, an error still appears when I activate virtual environment.

And here my code :

## webapp
app = Flask(__name__, template_folder='./')


@app.route('/prediction', methods=['POST', 'GET'])
def prediction():
    response =  pred(str(request.json['message']))
    return jsonify(response)

@app.route('/')
def main():
   return render_template('index.html')


if __name__ == '__main__':
   app.run(debug=True)

And the index

 <form action="http://127.0.0.1:5000/" method='POST' , 'GET'> <p>Text <input type="text" name="message" style="height:200px" /></p> <p><input type="submit" value="submit" /></p> </form> 

Answer 1

Virtual Environment

You mention in the post you had installed Tensorflow and it works without the virtual environment, so the error possibly comes from the fact that you haven't installed Tensorflow in the Virtual Environment itself. This is because when you create a Virtual Environment using Python, for such:

python -m venv venv

In the virtual environment, there is only the most recent of Python that you have available but not other packages you have in outside of Virtual Environment.

Solution: Activate the virtual environment, then install Tensorflow INSIDE of the virtual environment.

Flask Request

It is obvious that when you submit the form, it is a POST request, but in your index view, you only handle GET request. If you don't know what POST and GET request it, essentially:

• POST is used to send data to the server.
• GET is used to request data from the server.

In your case, you want to send the form data to the server, so it is a POST request. All you need to do is to modify your view function so that it could handle POST as well.

from flask import request

@app.route("/", methods=["POST", "GET"])
def main():
    // when the request is post request
    if request.method == "POST":
        // get data from the form
        data = request.form["message"]

        // do something here

    return render_template('index.html')

 <form action="http://127.0.0.1:5000/" method='POST'> <p>Text <input type="text" name="message" style="height:200px" /></p> <p><input type="submit" value="submit" /></p> </form> 

Jinja Template

Jinja is the template engine for Python. Basically, with the help of Jinja, you could pass variables from the server side to the client side and do all the logic in the client sides. In your case, you want to pass the data you got from the front-end back to the front-end, you could do:

from flask import request

@app.route("/", methods=["POST", "GET"])
def main():
    // when the request is post request
    if request.method == "POST":
        // get data from the form
        data = request.form["message"]

        // pass the data back to the front end
        return render_template("index.html", message=data)

    // message is none here because this is a get request
    return render_template('index.html', message=None)

and your index.html :

 <form action="http://127.0.0.1:5000/" method='POST' , 'GET'> <p>Text <input type="text" name="message" style="height:200px" /></p> <p><input type="submit" value="submit" /></p> </form> {% if message %} <h1>{{ message }}</h1> {% endif %} 

What happens in the front end? Well, it checks to see if the message variable from the server is None or not. If it is not None , then render the message variable, otherwise, do nothing.

You could learn more about Jinja here :)