code: def install_dependencies(plugins_directory, ostream=sys.stdout):
      '''
      Run ``on_plugin_install`` script for each plugin directory found in
      specified plugins directory.
  
      Parameters
      ----------
      plugins_directory : str
          File system path to directory containing zero or more plugin
          subdirectories.
      ostream : file-like
          Output stream for status messages (default: ``sys.stdout``).
      '''
      plugin_directories = plugins_directory.realpath().dirs()
  
      print >> ostream, 50 * '*'
      print >> ostream, 'Processing plugins:'
      print >> ostream, '\n'.join(['  - {}'.format(p)
                                      for p in plugin_directories])
      print >> ostream, '\n' + 50 * '-' + '\n'
  
      for plugin_dir_i in plugin_directories:
          try:
              on_plugin_install(plugin_dir_i, ostream=ostream)
          except RuntimeError, exception:
              print exception
          print >> ostream, '\n' + 50 * '-' + '\nf install_dependencies(plugins_directory, ostream=sys.stdout):
      '''
      Run ``on_plugin_install`` script for each plugin directory found in
      specified plugins directory.
  
      Parameters
      ----------
      plugins_directory : str
          File system path to directory containing zero or more plugin
          subdirectories.
      ostream : file-like
          Output stream for status messages (default: ``sys.stdout``).
      '''
      plugin_directories = plugins_directory.realpath().dirs()
  
      print >> ostream, 50 * '*'
      print >> ostream, 'Processing plugins:'
      print >> ostream, '\n'.join(['  - {}'.format(p)
                                      for p in plugin_directories])
      print >> ostream, '\n' + 50 * '-' + '\n'
  
      for plugin_dir_i in plugin_directories:
          try:
              on_plugin_install(plugin_dir_i, ostream=ostream)
          except RuntimeError, exception:
              print exception
          print >> ostream, '\n' + 50 * '-' + '\n'
docs: Run ``on_plugin_install`` script for each plugin directory found in
      specified plugins directory.
  
      Parameters
      ----------
      plugins_directory : str
          File system path to directory containing zero or more plugin
          subdirectories.
      ostream : file-like
          Output stream for status messages (default: ``sys.stdout``).