Object Oriented Python with Flask Server?

Question

I'm using Flask to expose some data-crunching code as a web service. I'd like to have some class variables that my Flask functions can access.

Let me walk you through where I'm stuck:

from flask import Flask app = Flask(__name__)  class MyServer:   def __init__(self):     globalData = json.load(filename)    @app.route('/getSomeData')   def getSomeData():     return random.choice(globalData) #select some random data to return  if __name__ == "__main__":   app.run(host='0.0.0.0') 

When I run getSomeData() outside of Flask, it works fine. But, when I run this with Flask, I get 500 internal server error. There's no magic here, and Flask has no idea that it's supposed to initialize a MyServer object. How can I feed an instance of MyServer to the app.run() command?

I could admit defeat and put globalData into a database instead. But, is there an other way?

Answer 1

You can create an instance of MyServer just outside the scope of your endpoints and access its attributes. This worked for me:

class MyServer:     def __init__(self):         self.globalData = "hello"  from flask import Flask app = Flask(__name__)  my_server = MyServer()  @app.route("/getSomeData") def getSomeData():     return my_server.globalData  if __name__ == "__main__":     app.run(host="0.0.0.0")