code: def is_plugin_installed(name):
      
      for directory in plugin_paths:
          if isdir(join(directory, name)):
              return True
      return False
docs: Check if a plugin is installed, even if it's not enabled.
  
      :param name: Name of the plugin to check.
      :type name: string
  
      :return: If the plugin is installed.
      :rtype: bool