title: Flask Error in Python: "Could not import webapp"
body: <p>I am trying to run flask, however, whenever I type in [flask run] it gives me an error: <code>Could not import webapp</code>. For reference, I am using Visual Studio Code and am running the following code:</p>
  <pre><code>from flask import Flask
  
  app = Flask(__name__)
  
  @app.route(&quot;/&quot;)
  def index():
      return &quot;Hello, world!&quot;
  </code></pre>
  <p>I get the following error message:</p>
  <pre><code> * Serving Flask app &quot;webapp&quot;
   * Environment: production
     WARNING: This is a development server. Do not use it in a production deployment.
     Use a production WSGI server instead.
   * Debug mode: off
  Usage: flask run [OPTIONS]
  Error: Could not import &quot;webapp&quot;.
  </code></pre>