title: Running Flask on bash: Could not import "app"
body: <p>I made this code on Flask:</p>
  
  <pre><code>from flask import Flask
  
  app = Flask(__name__)
  
  @app.route('/')
  def index():
      return "hi"
  </code></pre>
  
  <p>Even so, fi I try to run it with <code>flask run</code> it shows this message:</p>
  
  <pre><code>* Serving Flask app "app.py"
   * 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 "app".
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>Edit: 
  App structure:</p>
  
  <pre><code>website/
    | - app.py
  </code></pre>