plex media server library refresh all libraries.

force-refresh-plex-library.py

#!/usr/bin/env python
import urllib
from xml.dom import minidom

host = 'localhost'
source_type = ['movie', 'show'] # Valid values: artist (for music), movie, show (for tv)
base_url = 'http://%s:32400/library/sections' % host
refresh_url = '%s/%%s/refresh?force=1' % base_url

try:
  xml_sections = minidom.parse(urllib.urlopen(base_url))
  sections = xml_sections.getElementsByTagName('Directory')
  for s in sections:
    if s.getAttribute('type') in source_type:
      url = refresh_url % s.getAttribute('key')
      x = urllib.urlopen(url)
except:
  pass

refresh-plex-library.py

#!/usr/bin/env python
import urllib
from xml.dom import minidom

host = 'localhost'
source_type = ['movie', 'show'] # Valid values: artist (for music), movie, show (for tv)
base_url = 'http://%s:32400/library/sections' % host
refresh_url = '%s/%%s/refresh' % base_url

try:
  xml_sections = minidom.parse(urllib.urlopen(base_url))
  sections = xml_sections.getElementsByTagName('Directory')
  for s in sections:
    if s.getAttribute('type') in source_type:
      url = refresh_url % s.getAttribute('key')
      x = urllib.urlopen(url)
except:
  pass

There is no need to do per section if your intent is to refresh all. Example:

/library/sections/all/refresh?force=1