code: def view_plugins(category=None):
      
      if category is not None:
          if category == 'parsers':
              return {
                  name: {"descript": klass.plugin_descript,
                         "regex": klass.file_regex}
                  for name, klass in _all_plugins[category].items()
              }
          return {
              name: klass.plugin_descript
              for name, klass in _all_plugins[category].items()
          }
      else:
          return {cat: {name: klass.plugin_descript
                        for name, klass in plugins.items()}
                  for cat, plugins in _all_plugins.items()}
docs: return a view of the loaded plugin names and descriptions
  
      Parameters
      ----------
      category : None or str
          if str, apply for single plugin category
  
      Examples
      --------
  
      >>> from pprint import pprint
      >>> pprint(view_plugins())
      {'decoders': {}, 'encoders': {}, 'parsers': {}}
  
      >>> class DecoderPlugin(object):
      ...     plugin_name = 'example'
      ...     plugin_descript = 'a decoder for dicts containing _example_ key'
      ...     dict_signature = ('_example_',)
      ...
      >>> errors = load_plugin_classes([DecoderPlugin])
  
      >>> pprint(view_plugins())
      {'decoders': {'example': 'a decoder for dicts containing _example_ key'},
       'encoders': {},
       'parsers': {}}
  
      >>> view_plugins('decoders')
      {'example': 'a decoder for dicts containing _example_ key'}
  
      >>> unload_all_plugins()