text: from __future__ import absolute_import
  
  import logging
  import os
  import tempfile
  import re
  
  from pip.compat import urlparse
  from pip.utils import rmtree, display_path, call_subprocess
  from pip.vcs import vcs, VersionControl
  from pip.download import path_to_url
  
  
  logger = logging.getLogger(__name__)
  
  
  class Bazaar(VersionControl):
      name = 'bzr'
      dirname = '.bzr'
      repo_name = 'branch'
      schemes = (
          'bzr', 'bzr+http', 'bzr+https', 'bzr+ssh', 'bzr+sftp', 'bzr+ftp',
          'bzr+lp',
      )
  
      def __init__(self, url=None, *args, **kwargs):
          super(Bazaar, self).__init__(url, *args, **kwargs)
          # Python >= 2.7.4, 3.3 doesn't have uses_fragment or non_hierarchical
          # Register lp but do not expose as a scheme to support bzr+lp.
          if getattr(urlparse, 'uses_fragment', None):
              urlparse.uses_fragment.extend(['lp'])
              urlparse.non_hierarchical.extend(['lp'])
  
      def export(self, location):
          """
          Export the Bazaar repository at the url to the destination location
          """
          temp_dir = tempfile.mkdtemp('-export', 'pip-')
          self.unpack(temp_dir)
          if os.path.exists(location):
              # Remove the location to make sure Bazaar can export it correctly
              rmtree(location)
          try:
              call_subprocess([self.cmd, 'export', location], cwd=temp_dir,
                              filter_stdout=self._filter, show_stdout=False)
          finally:
              rmtree(temp_dir)
  
      def switch(self, dest, url, rev_options):
          call_subprocess([self.cmd, 'switch', url], cwd=dest)
  
      def update(self, dest, rev_options):
          call_subprocess(
              [self.cmd, 'pull', '-q'] + rev_options, cwd=dest)
  
      def obtain(self, dest):
          url, rev = self.get_url_rev()
          if rev:
              rev_options = ['-r', rev]
              rev_display = ' (to revision %s)' % rev
          else:
              rev_options = []
              rev_display = ''
          if self.check_destination(dest, url, rev_options, rev_display):
              logger.info(
                  'Checking out %s%s to %s',
                  url,
                  rev_display,
                  display_path(dest),
              )
              call_subprocess(
                  [self.cmd, 'branch', '-q'] + rev_options + [url, dest])
  
      def get_url_rev(self):
          # hotfix the URL scheme after removing bzr+ from bzr+ssh:// readd it
          url, rev = super(Bazaar, self).get_url_rev()
          if url.startswith('ssh://'):
              url = 'bzr+' + url
          return url, rev
  
      def get_url(self, location):
          urls = call_subprocess(
              [self.cmd, 'info'], show_stdout=False, cwd=location)
          for line in urls.splitlines():
              line = line.strip()
              for x in ('checkout of branch: ',
                        'parent branch: '):
                  if line.startswith(x):
                      repo = line.split(x)[1]
                      if self._is_local_repository(repo):
                          return path_to_url(repo)
                      return repo
          return None
  
      def get_revision(self, location):
          revision = call_subprocess(
              [self.cmd, 'revno'], show_stdout=False, cwd=location)
          return revision.splitlines()[-1]
  
      def get_tag_revs(self, location):
          tags = call_subprocess(
              [self.cmd, 'tags'], show_stdout=False, cwd=location)
          tag_revs = []
          for line in tags.splitlines():
              tags_match = re.search(r'([.\w-]+)\s*(.*)$', line)
              if tags_match:
                  tag = tags_match.group(1)
                  rev = tags_match.group(2)
                  tag_revs.append((rev.strip(), tag.strip()))
          return dict(tag_revs)
  
      def get_src_requirement(self, dist, location, find_tags):
          repo = self.get_url(location)
          if not repo:
              return None
          if not repo.lower().startswith('bzr:'):
              repo = 'bzr+' + repo
          egg_project_name = dist.egg_name().split('-', 1)[0]
          current_rev = self.get_revision(location)
          tag_revs = self.get_tag_revs(location)
  
          if current_rev in tag_revs:
              # It's a tag
              full_egg_name = '%s-%s' % (egg_project_name, tag_revs[current_rev])
          else:
              full_egg_name = '%s-dev_r%s' % (dist.egg_name(), current_rev)
          return '%s@%s#egg=%s' % (repo, current_rev, full_egg_name)
  
  
  vcs.register(Bazaar)
  