old_contents: #!/usr/bin/env python
  
  from os import path
  import filters
  import auxfile
  from formatters import label
  from formatters.backends import latex
  
  __version__ = "0.1"
  
  def make_bibliography(aux_filename, bib_format='bib', bib_encoding=None, latex_encoding=None):
      filename = path.splitext(aux_filename)[0]
      aux_data = auxfile.parse_file(aux_filename)
  
      bib_parser = filters.find_filter('input', bib_format)
      if bib_encoding is not None:
          try:
              bib_parser.set_encoding(bib_encoding)
          except AttributeError:
              pass
  
      bib_data = bib_parser.parse_file(path.extsep.join([aux_data.data, bib_parser.extension]))
      
      entries = prepare_entries(bib_data, aux_data)
      del bib_data
  
      backend = latex
      style = import_style(aux_data.style).Formatter(backend)
      formatted_entries = style.format_entries(entries)
      backend.Writer(latex_encoding).write_bibliography(formatted_entries, path.extsep.join([filename, 'bbl']))
  
  def import_style(name):
      m = __import__('pybtex.formatters.styles', globals(), locals(), [name])
      return getattr(m, name)
  
  def prepare_entries(bib_data, aux_data):
      n = 1
      entries = []
      for key in aux_data.citations:
          print key
          entry = bib_data[key]
          entry.number = n
          entry.key = key
          entry.label = label.number(entry)
          entries.append(entry)
          n += 1
      def l(e):
          return e.label
      entries.sort(key=l)
      return entries
  
  def parse_filename(filename):
      dot = filename.rfind('.')
      if dot == -1:
          return filename, None
      else:
          return (filename[:dot], filename[dot + 1:])
  
  
new_contents: #!/usr/bin/env python
  
  from os import path
  import filters
  import auxfile
  from formatters import label
  from formatters.backends import latex
  
  __version__ = "0.1"
  
  def make_bibliography(aux_filename, bib_format='bib', bib_encoding=None, latex_encoding=None):
      filename = path.splitext(aux_filename)[0]
      aux_data = auxfile.parse_file(aux_filename)
  
      bib_parser = filters.find_filter('input', bib_format)
      if bib_encoding is not None:
          try:
              bib_parser.set_encoding(bib_encoding)
          except AttributeError:
              pass
  
      bib_data = bib_parser.parse_file(path.extsep.join([aux_data.data, bib_parser.extension]))
      
      entries = prepare_entries(bib_data, aux_data)
      del bib_data
  
      backend = latex
      style = import_style(aux_data.style).Formatter(backend)
      formatted_entries = style.format_entries(entries)
      del entries
      backend.Writer(latex_encoding).write_bibliography(formatted_entries, path.extsep.join([filename, 'bbl']))
  
  def import_style(name):
      m = __import__('pybtex.formatters.styles', globals(), locals(), [name])
      return getattr(m, name)
  
  def prepare_entries(bib_data, aux_data):
      n = 1
      entries = []
      for key in aux_data.citations:
          print key
          entry = bib_data[key]
          entry.number = n
          entry.key = key
          entry.label = label.number(entry)
          entries.append(entry)
          n += 1
      def l(e):
          return e.label
      entries.sort(key=l)
      return entries
  
  def parse_filename(filename):
      dot = filename.rfind('.')
      if dot == -1:
          return filename, None
      else:
          return (filename[:dot], filename[dot + 1:])
  
  
subject: delete entries right after use (might conserve some memory =)