code: def find_user_by_name(username):
      
      if db is not None:
          uid = db.hget('users', username)
          if uid:
              return get_user(uid)
      else:
          for uid, u in app.config['COIL_USERS'].items():
              if u['username'] == username:
                  return get_user(uid)
docs: Get an user by their username.
  
      :param str username: Username to find
      :return: the user
      :rtype: User object or None