import stem.descriptor.remote

for desc in stem.descriptor.remote.get_server_descriptors():
  if desc.exit_policy.is_exiting_allowed():
    print('  %s (%s)' % (desc.nickname, desc.fingerprint))

from stem.descriptor.remote import DescriptorDownloader

downloader = DescriptorDownloader(
  use_mirrors = True,
  timeout = 10,
)

query = downloader.get_server_descriptors()

print('Exit Relays:')

try:
  for desc in query.run():
    if desc.exit_policy.is_exiting_allowed():
      print('  %s (%s)' % (desc.nickname, desc.fingerprint))

  print
  print('Query took %0.2f seconds' % query.runtime)
except Exception as exc:
  print('Unable to retrieve the server descriptors: %s' % exc)

get_instance - Provides a singleton DescriptorDownloader used for...
  |- their_server_descriptor - provides the server descriptor of the relay we download from
  |- get_server_descriptors - provides present server descriptors
  |- get_extrainfo_descriptors - provides present extrainfo descriptors
  |- get_microdescriptors - provides present microdescriptors with the given digests
  |- get_consensus - provides the present consensus or router status entries
  |- get_bandwidth_file - provides bandwidth heuristics used to make the next consensus
  +- get_detached_signatures - authority signatures used to make the next consensus

Query - Asynchronous request to download tor descriptors
  |- start - issues the query if it isn't already running
  +- run - blocks until the request is finished and provides the results

DescriptorDownloader - Configurable class for issuing queries
  |- use_directory_mirrors - use directory mirrors to download future descriptors
  |- their_server_descriptor - provides the server descriptor of the relay we download from
  |- get_server_descriptors - provides present server descriptors
  |- get_extrainfo_descriptors - provides present extrainfo descriptors
  |- get_microdescriptors - provides present microdescriptors with the given digests
  |- get_consensus - provides the present consensus or router status entries
  |- get_vote - provides an authority's vote for the next consensus
  |- get_key_certificates - provides present authority key certificates
  |- get_bandwidth_file - provides bandwidth heuristics used to make the next consensus
  |- get_detached_signatures - authority signatures used to make the next consensus
  +- query - request an arbitrary descriptor resource