title: ModuleNotFoundError: No module named '__main__.web_app'; '__main__' is not a package while importing package from sub folder
body: <p>I'm getting above error while running my app. I want to import app from web_app/<strong>init</strong>.py into run.py file to run on gevent. My project structure is like:</p>
  
  <pre><code>myapp
   |---config.ini
   |---run.py
   |---web_app
          |----__init__.py
  
  
  run.py
  
  from gevent.pywsgi import WSGIServer
  import configparser
  
  from .web_app import app
  # from web_app.__init__ import app
  
  config = configparser.ConfigParser()
  config.read('C:/workspace/Python/myapp/config.ini')
  PORT = config.get('SERVER', 'PORT')
  PORT = int(PORT)
  
  
  if __name__ == '__main__':
      print('Serving on port ', PORT)
      WSGIServer(('localhost', PORT), app).serve_forever()
  </code></pre>
  
  <p>__init.py</p>
  
  <pre><code>from flask import Flask
  app = Flask(__name__)
  app.config['APPLICATION_ROOT'] = '/myapp'
  logger = log_configuration.get_logger(__name__)
  
  def simple(env, resp):
     resp(b'200 OK', [(b'Content-Type', b'application/json')])
     return [b'Hello Verimed User']
  
  @app.route('/test', methods=['GET'])
  def test():
     return jsonify({'tasks': "task"})
  </code></pre>
  
  <p>If I keep run.py beside <strong>init</strong> then it's working fine. But I want to keep run.py outside web_app folder.
  How to rosolve this. I tried all the way.</p>