old_contents: from flask import Flask, render_template
  app = Flask(__name__)
  
  @app.route('/')
  def hello_world():
      l_user = 'admin'
      l_message = 'Welcome!'
      return render_template('index.tpl', p_user = l_user, p_message = l_message)
  
  if __name__ == '__main__':
      app.run()
  
new_contents: from flask import Flask, render_template
  app = Flask(__name__)
  
  @app.route('/')
  def hello_world():
      l_user = 'admin'
      l_message = 'Welcome!'
      return render_template('index.tpl', p_user = l_user, p_message = l_message)
  
  def adjust_system_path():
          """
              Adjust the system path, so we can search in custom dirs for modules.
          """
          sys.path.append('fade')
          sys.path.append('fade/static')
          sys.path.append('fade/static/img')
          sys.path.append('fade/static/js')
          sys.path.append('fade/static/css')
          sys.path.append('fade/templates')
          sys.path.append('instance')
          
  if __name__ == '__main__':
      adjust_system_path()
      app.run()
  
subject: Adjust system_path.