text: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  #
  # License: MIT (see LICENSE file provided)
  # vim600: fdm=marker tabstop=4 shiftwidth=4 expandtab ai
  
  # Description {{{
  """
  **polib** allows you to manipulate, create, modify gettext files (pot, po
  and mo files).  You can load existing files, iterate through it's entries,
  add, modify entries, comments or metadata, etc... or create new po files
  from scratch.
  
  **polib** provides a simple and pythonic API, exporting only three
  convenience functions (*pofile*, *mofile* and *detect_encoding*), and the
  four core classes, *POFile*, *MOFile*, *POEntry* and *MOEntry* for creating
  new files/entries.
  
  **Basic example**:
  
  >>> import polib
  >>> # load an existing po file
  >>> po = polib.pofile('tests/test_utf8.po')
  >>> for entry in po:
  ...     # do something with entry...
  ...     pass
  >>> # add an entry
  >>> entry = polib.POEntry(msgid='Welcome', msgstr='Bienvenue')
  >>> entry.occurrences = [('welcome.py', '12'), ('anotherfile.py', '34')]
  >>> po.append(entry)
  >>> # to save our modified po file:
  >>> # po.save()
  >>> # or you may want to compile the po file
  >>> # po.save_as_mofile('tests/test_utf8.mo')
  """
  # }}}
  
  __author__    = 'David JEAN LOUIS <izimobil@gmail.com>'
  __version__   = '0.3.1'
  
  
  # dependencies {{{
  try:
      import struct
      import textwrap
      import warnings
  except ImportError, exc:
      raise ImportError('polib requires python 2.3 or later with the standard' \
          ' modules "struct", "textwrap" and "warnings" (details: %s)' % exc)
  # }}}
  
  __all__ = ['pofile', 'POFile', 'POEntry', 'mofile', 'MOFile', 'MOEntry',
             'detect_encoding', 'quote', 'unquote']
  
  # shortcuts for performance improvement {{{
  # yes, yes, this is quite ugly but *very* efficient
  _dictget    = dict.get
  _listappend = list.append
  _listpop    = list.pop
  _strjoin    = str.join
  _strsplit   = str.split
  _strstrip   = str.strip
  _strreplace = str.replace
  _textwrap   = textwrap.wrap
  # }}}
  
  default_encoding = 'utf-8'
  
  def pofile(fpath, **kwargs):
      """
      Convenience function that parse the po/pot file *fpath* and return
      a POFile instance.
  
      **Keyword arguments**:
        - *fpath*: string, full or relative path to the po/pot file to parse
        - *wrapwidth*: integer, the wrap width, only useful when -w option was
          passed to xgettext (optional, default to 78)
        - *autodetect_encoding*: boolean, if set to False the function will
          not try to detect the po file encoding (optional, default to True)
        - *encoding*: string, an encoding, only relevant if autodetect_encoding
          is set to False
  
      **Example**:
  
      >>> import polib
      >>> po = polib.pofile('tests/test_utf8.po')
      >>> po #doctest: +ELLIPSIS
      <POFile instance at ...>
      >>> import os, tempfile
      >>> for fname in ['test_iso-8859-15.po', 'test_utf8.po']:
      ...     orig_po = polib.pofile('tests/'+fname)
      ...     tmpf = tempfile.NamedTemporaryFile().name
      ...     orig_po.save(tmpf)
      ...     try:
      ...         new_po = polib.pofile(tmpf)
      ...         for old, new in zip(orig_po, new_po):
      ...             if old.msgid != new.msgid:
      ...                 old.msgid
      ...                 new.msgid
      ...             if old.msgstr != new.msgstr:
      ...                 old.msgid
      ...                 new.msgid
      ...     finally:
      ...         os.unlink(tmpf)
      """
      # pofile {{{
      if _dictget(kwargs, 'autodetect_encoding', True) == True:
          enc = detect_encoding(fpath)
      else:
          enc = _dictget(kwargs, 'encoding', default_encoding)
      parser = _POFileParser(fpath)
      instance = parser.parse()
      instance.wrapwidth = _dictget(kwargs, 'wrapwidth', 78)
      instance.encoding  = enc
      return instance
      # }}}
  
  
  def mofile(fpath, **kwargs):
      """
      Convenience function that parse the mo file *fpath* and return
      a MOFile instance.
  
      **Keyword arguments**:
        - *fpath*: string, full or relative path to the mo file to parse
        - *wrapwidth*: integer, the wrap width, only useful when -w option was
          passed to xgettext to generate the po file that was used to format
          the mo file (optional, default to 78)
        - *autodetect_encoding*: boolean, if set to False the function will
          not try to detect the po file encoding (optional, default to True)
        - *encoding*: string, an encoding, only relevant if autodetect_encoding
          is set to False
  
      **Example**:
  
      >>> import polib
      >>> mo = polib.mofile('tests/test_utf8.mo')
      >>> mo #doctest: +ELLIPSIS
      <MOFile instance at ...>
      >>> import os, tempfile
      >>> for fname in ['test_iso-8859-15.mo', 'test_utf8.mo']:
      ...     orig_mo = polib.mofile('tests/'+fname)
      ...     tmpf = tempfile.NamedTemporaryFile().name
      ...     orig_mo.save(tmpf)
      ...     try:
      ...         new_mo = polib.mofile(tmpf)
      ...         for old, new in zip(orig_mo, new_mo):
      ...             if old.msgid != new.msgid:
      ...                 old.msgstr
      ...                 new.msgstr
      ...     finally:
      ...         os.unlink(tmpf)
      """
      # mofile {{{
      if _dictget(kwargs, 'autodetect_encoding', True) == True:
          enc = detect_encoding(fpath)
      else:
          enc = _dictget(kwargs, 'encoding', default_encoding)
      parser = _MOFileParser(fpath)
      instance = parser.parse()
      instance.wrapwidth = _dictget(kwargs, 'wrapwidth', 78)
      instance.encoding = enc
      return instance
      # }}}
  
  
  def detect_encoding(fpath):
      """
      Try to detect the encoding used by the file *fpath*. The function will
      return polib default *encoding* if it's unable to detect it.
  
      **Keyword argument**:
        - *fpath*: string, full or relative path to the mo file to parse.
  
      **Examples**:
  
      >>> print detect_encoding('tests/test_noencoding.po')
      utf-8
      >>> print detect_encoding('tests/test_utf8.po')
      UTF-8
      >>> print detect_encoding('tests/test_utf8.mo')
      UTF-8
      >>> print detect_encoding('tests/test_iso-8859-15.po')
      ISO_8859-15
      >>> print detect_encoding('tests/test_iso-8859-15.mo')
      ISO_8859-15
      """
      # detect_encoding {{{
      import re
      rx = re.compile(r'"?Content-Type:.+? charset=([\w_\-:\.]+)')
      f = open(fpath)
      for l in f:
          match = rx.search(l)
          if match:
              f.close()
              return _strstrip(match.group(1))
      f.close()
      return default_encoding
      # }}}
  
  
  def quote(st):
      """
      Quote and return the given string *st*.
  
      **Examples**:
  
      >>> quote('\\t and \\n and \\r and " and \\\\')
      '\\\\t and \\\\n and \\\\r and \\\\" and \\\\\\\\'
      """
      # quote {{{
      st = _strreplace(st, '\\', r'\\')
      st = _strreplace(st, '\t', r'\t')
      st = _strreplace(st, '\r', r'\r')
      st = _strreplace(st, '\n', r'\n')
      st = _strreplace(st, '\"', r'\"')
      return st
      # }}}
  
  
  def unquote(st):
      """
      Unquote and return the given string *st*.
  
      **Examples**:
  
      >>> unquote('\\\\t and \\\\n and \\\\r and \\\\" and \\\\\\\\')
      '\\t and \\n and \\r and " and \\\\'
      """
      # unquote {{{
      st = _strreplace(st, r'\"', '"')
      st = _strreplace(st, r'\n', '\n')
      st = _strreplace(st, r'\r', '\r')
      st = _strreplace(st, r'\t', '\t')
      st = _strreplace(st, r'\\', '\\')
      return st
      # }}}
  
  
  class _BaseFile(list):
      """
      Common parent class for POFile and MOFile classes.
      This class must **not** be instanciated directly.
      """
      # class _BaseFile {{{
  
  
      def __init__(self, fpath=None, wrapwidth=78, encoding=default_encoding):
          """
          Constructor.
  
          **Keyword arguments**:
            - *fpath*: string, path to po or mo file
            - *wrapwidth*: integer, the wrap width, only useful when -w option
              was passed to xgettext to generate the po file that was used to
              format the mo file, default to 78 (optional).
          """
          list.__init__(self)
          # the opened file handle
          self.fpath = fpath
          # the width at which lines should be wrapped
          self.wrapwidth = wrapwidth
          # the file encoding
          self.encoding = encoding
          # header
          self.header = ''
          # both po and mo files have metadata
          self.metadata = {}
          self.metadata_is_fuzzy = 0
  
      def __str__(self):
          """String representation of the file."""
          ret = []
          entries = [self.metadata_as_entry()] + \
                    [e for e in self if not e.obsolete]
          for entry in entries:
              _listappend(ret, entry.__str__(self.wrapwidth))
          for entry in self.obsolete_entries():
              _listappend(ret, entry.__str__(self.wrapwidth))
          return _strjoin('\n', ret)
  
      def __repr__(self):
          """Return the official string representation of the object."""
          return '<%s instance at %x>' % (self.__class__.__name__, id(self))
  
      def metadata_as_entry(self):
          """Return the metadata as an entry"""
          e = POEntry(msgid='')
          mdata = self.ordered_metadata()
          if mdata:
              strs = []
              for name, value in mdata:
                  # Strip whitespace off each line in a multi-line entry
                  value = _strjoin('\n', [_strstrip(v)
                                          for v in _strsplit(value, '\n')])
                  _listappend(strs, '%s: %s' % (name, value))
              e.msgstr = _strjoin('\n', strs) + '\n'
          return e
  
      def save(self, fpath=None, repr_method='__str__'):
          """
          Save the po file to file *fpath* if no file handle exists for
          the object. If there's already an open file and no fpath is
          provided, then the existing file is rewritten with the modified
          data.
  
          **Keyword arguments**:
            - *fpath*: string, full or relative path to the file.
            - *repr_method*: string, the method to use for output.
          """
          if self.fpath is None and fpath is None:
              raise IOError('You must provide a file path to save() method')
          contents = getattr(self, repr_method)()
          if fpath is None:
              fpath = self.fpath
          mode = 'w'
          if repr_method == 'to_binary':
              mode += 'b'
          fhandle = open(fpath, mode)
          fhandle.write(contents)
          fhandle.close()
  
      def find(self, st, by='msgid'):
          """
          Find entry which msgid (or property identified by the *by*
          attribute) matches the string *st*.
  
          **Keyword arguments**:
            - *st*: string, the string to search for
            - *by*: string, the comparison attribute
  
          **Examples**:
  
          >>> po = pofile('tests/test_utf8.po')
          >>> entry = po.find('Thursday')
          >>> entry.msgstr
          'Jueves'
          >>> entry = po.find('Some unexistant msgid')
          >>> entry is None
          True
          >>> entry = po.find('Jueves', 'msgstr')
          >>> entry.msgid
          'Thursday'
          """
          try:
              return [e for e in self if getattr(e, by) == st][0]
          except IndexError:
              return None
  
      def ordered_metadata(self):
          """
          Convenience method that return the metadata ordered. The return
          value is list of tuples (metadata name, metadata_value).
          """
          # copy the dict first
          metadata = self.metadata.copy()
          data_order = [
              'Project-Id-Version',
              'Report-Msgid-Bugs-To',
              'POT-Creation-Date',
              'PO-Revision-Date',
              'Last-Translator',
              'Language-Team',
              'MIME-Version',
              'Content-Type',
              'Content-Transfer-Encoding'
          ]
          ordered_data = []
          for data in data_order:
              try:
                  value = metadata.pop(data)
                  _listappend(ordered_data, (data, value))
              except KeyError:
                  pass
          # the rest of the metadata won't be ordered there are no specs for this
          keys = metadata.keys()
          keys.sort()
          for data in keys:
              value = metadata[data]
              _listappend(ordered_data, (data, value))
          return ordered_data
  
      def to_binary(self):
          """Return the mofile binary representation."""
          import struct
          import array
          output = ''
          offsets = []
          ids = strs = ''
          entries = self.translated_entries()
          # the keys are sorted in the .mo file
          def cmp(_self, other):
              if _self.msgid > other.msgid:
                  return 1
              elif _self.msgid < other.msgid:
                  return -1
              else:
                  return 0
          entries.sort(cmp)
          # add metadata entry
          mentry = self.metadata_as_entry()
          mentry.msgstr = _strreplace(mentry.msgstr, '\\n', '').lstrip() + '\n'
          entries = [mentry] + entries
          entries_len = len(entries)
          for e in entries:
              # For each string, we need size and file offset.  Each string is
              # NUL terminated; the NUL does not count into the size.
              msgid = e._decode(e.msgid)
              msgstr = e._decode(e.msgstr)
              offsets.append((len(ids), len(msgid), len(strs), len(msgstr)))
              ids  += msgid  + '\0'
              strs += msgstr + '\0'
          # The header is 7 32-bit unsigned integers.
          keystart = 7*4+16*entries_len
          # and the values start after the keys
          valuestart = keystart + len(ids)
          koffsets = []
          voffsets = []
          # The string table first has the list of keys, then the list of values.
          # Each entry has first the size of the string, then the file offset.
          for o1, l1, o2, l2 in offsets:
              koffsets += [l1, o1+keystart]
              voffsets += [l2, o2+valuestart]
          offsets = koffsets + voffsets
          output = struct.pack("Iiiiiii",
                               0x950412de,        # Magic number
                               0,                 # Version
                               entries_len,       # # of entries
                               7*4,               # start of key index
                               7*4+entries_len*8, # start of value index
                               0, 0)              # size and offset of hash table
          output += array.array("i", offsets).tostring()
          output += ids
          output += strs
          return output
      # }}}
  
  
  class POFile(_BaseFile):
      '''
      Po (or Pot) file reader/writer.
      POFile objects inherit the list objects methods.
  
      **Example**:
  
      >>> po = POFile()
      >>> entry1 = POEntry(
      ...     msgid="Some english text",
      ...     msgstr="Un texte en anglais"
      ... )
      >>> entry1.occurrences = [('testfile', 12),('another_file', 1)]
      >>> entry1.comment = "Some useful comment"
      >>> entry2 = POEntry(
      ...     msgid="I need my dirty cheese",
      ...     msgstr="Je veux mon sale fromage"
      ... )
      >>> entry2.occurrences = [('testfile', 15),('another_file', 5)]
      >>> entry2.comment = "Another useful comment"
      >>> entry3 = POEntry(
      ...     msgid='Some entry with quotes " \\"',
      ...     msgstr=u'Un message unicode avec des quotes " \\"'
      ... )
      >>> entry3.comment = "Test string quoting"
      >>> po.append(entry1)
      >>> po.append(entry2)
      >>> po.append(entry3)
      >>> po.header = "Some Header"
      >>> print po
      # Some Header
      msgid ""
      msgstr ""
      <BLANKLINE>
      #. Some useful comment
      #: testfile:12 another_file:1
      msgid "Some english text"
      msgstr "Un texte en anglais"
      <BLANKLINE>
      #. Another useful comment
      #: testfile:15 another_file:5
      msgid "I need my dirty cheese"
      msgstr "Je veux mon sale fromage"
      <BLANKLINE>
      #. Test string quoting
      msgid "Some entry with quotes \\" \\""
      msgstr "Un message unicode avec des quotes \\" \\""
      <BLANKLINE>
      '''
      # class POFile {{{
  
      def __str__(self):
          """Return the string representation of the po file"""
          ret, headers = '', _strsplit(self.header, '\n')
          for header in headers:
              if header[:1] in [',', ':']:
                  ret += '#%s\n' % header
              else:
                  ret += '# %s\n' % header
          return ret + _BaseFile.__str__(self)
  
      def save_as_mofile(self, fpath):
          """
          Save the binary representation of the file to *fpath*.
  
          **Keyword arguments**:
            - *fpath*: string, full or relative path to the file.
          """
          _BaseFile.save(self, fpath, 'to_binary')
  
      def percent_translated(self):
          """
          Convenience method that return the percentage of translated
          messages.
  
          **Example**:
  
          >>> import polib
          >>> po = polib.pofile('tests/test_pofile_helpers.po')
          >>> po.percent_translated()
          50
          >>> po = POFile()
          >>> po.percent_translated()
          100
          """
          total = len([e for e in self if not e.obsolete])
          if total == 0:
              return 100
          translated = len(self.translated_entries())
          return int((100.00 / float(total)) * translated)
  
      def translated_entries(self):
          """
          Convenience method that return a list of translated entries.
  
          **Example**:
  
          >>> import polib
          >>> po = polib.pofile('tests/test_pofile_helpers.po')
          >>> len(po.translated_entries())
          6
          """
          return [e for e in self if e.translated() and not e.obsolete]
  
      def untranslated_entries(self):
          """
          Convenience method that return a list of untranslated entries.
  
          **Example**:
  
          >>> import polib
          >>> po = polib.pofile('tests/test_pofile_helpers.po')
          >>> len(po.untranslated_entries())
          6
          """
          return [e for e in self if not e.translated() and not e.obsolete]
  
      def fuzzy_entries(self):
          """
          Convenience method that return the list of 'fuzzy' entries.
  
          **Example**:
  
          >>> import polib
          >>> po = polib.pofile('tests/test_pofile_helpers.po')
          >>> len(po.fuzzy_entries())
          2
          """
          return [e for e in self if 'fuzzy' in e.flags]
  
      def obsolete_entries(self):
          """
          Convenience method that return the list of obsolete entries.
  
          **Example**:
  
          >>> import polib
          >>> po = polib.pofile('tests/test_pofile_helpers.po')
          >>> len(po.obsolete_entries())
          4
          """
          return [e for e in self if e.obsolete]
  
      def merge(self, refpot):
          """
          XXX this could not work if encodings are different, needs thinking
          and general refactoring of how polib handles encoding...
  
          Convenience method that merge the current pofile with the pot file
          provided. It behaves exactly as the gettext msgmerge utility:
  
            - comments of this file will be preserved, but extracted comments
              and occurrences will be discarded
            - any translations or comments in the file will be discarded,
              however dot comments and file positions will be preserved
  
          **Keyword argument**:
            - *refpot*: object POFile, the reference catalog.
  
          **Example**:
  
          >>> import polib
          >>> refpot = polib.pofile('tests/test_merge.pot')
          >>> po = polib.pofile('tests/test_merge_before.po')
          >>> po.merge(refpot)
          >>> expected_po = polib.pofile('tests/test_merge_after.po')
          >>> str(po) == str(expected_po)
          True
          """
          for entry in refpot:
              e = self.find(entry.msgid)
              if e is None:
                  # entry is not in the po file, we must add it
                  # entry is created with msgid, occurrences and comment
                  self.append(POEntry(
                      msgid=entry.msgid,
                      occurrences=entry.occurrences,
                      comment=entry.comment
                  ))
              else:
                  # entry found, we update it...
                  e.occurrences = entry.occurrences
                  e.comment = entry.comment
          # ok, now we must "obsolete" entries that are not in the refpot
          # anymore
          for entry in self:
              if refpot.find(entry.msgid) is None:
                  entry.obsolete = True
      # }}}
  
  
  class MOFile(_BaseFile):
      '''
      Mo file reader/writer.
      MOFile objects inherit the list objects methods.
  
      **Example**:
  
      >>> mo = MOFile()
      >>> entry1 = POEntry(
      ...     msgid="Some english text",
      ...     msgstr="Un texte en anglais"
      ... )
      >>> entry2 = POEntry(
      ...     msgid="I need my dirty cheese",
      ...     msgstr="Je veux mon sale fromage"
      ... )
      >>> entry3 = MOEntry(
      ...     msgid='Some entry with quotes " \\"',
      ...     msgstr=u'Un message unicode avec des quotes " \\"'
      ... )
      >>> mo.append(entry1)
      >>> mo.append(entry2)
      >>> mo.append(entry3)
      >>> print mo
      msgid ""
      msgstr ""
      <BLANKLINE>
      msgid "Some english text"
      msgstr "Un texte en anglais"
      <BLANKLINE>
      msgid "I need my dirty cheese"
      msgstr "Je veux mon sale fromage"
      <BLANKLINE>
      msgid "Some entry with quotes \\" \\""
      msgstr "Un message unicode avec des quotes \\" \\""
      <BLANKLINE>
      '''
      # class MOFile {{{
  
      def __init__(self, fpath=None, wrapwidth=78):
          """
          MOFile constructor.
          See _BaseFile.__construct.
          """
          _BaseFile.__init__(self, fpath, wrapwidth)
          self.magic_number = None
          self.version = 0
  
      def save_as_pofile(self, fpath):
          """
          Save the string representation of the file to *fpath*.
  
          **Keyword argument**:
            - *fpath*: string, full or relative path to the file.
          """
          _BaseFile.save(self, fpath)
  
      def save(self, fpath):
          """
          Save the binary representation of the file to *fpath*.
  
          **Keyword argument**:
            - *fpath*: string, full or relative path to the file.
          """
          _BaseFile.save(self, fpath, 'to_binary')
  
      def percent_translated(self):
          """
          Convenience method to keep the same interface with POFile instances.
          """
          return 100
  
      def translated_entries(self):
          """
          Convenience method to keep the same interface with POFile instances.
          """
          return self
  
      def untranslated_entries(self):
          """
          Convenience method to keep the same interface with POFile instances.
          """
          return []
  
      def fuzzy_entries(self):
          """
          Convenience method to keep the same interface with POFile instances.
          """
          return []
  
      def obsolete_entries(self):
          """
          Convenience method to keep the same interface with POFile instances.
          """
          return []
      # }}}
  
  
  class _BaseEntry(object):
      """
      Base class for POEntry or MOEntry objects.
      This class must *not* be instanciated directly.
      """
      # class _BaseEntry {{{
  
      def __init__(self, *args, **kwargs):
          """Base Entry constructor."""
          self.msgid = _dictget(kwargs, 'msgid', '')
          self.msgstr = _dictget(kwargs, 'msgstr', '')
          self.msgid_plural = _dictget(kwargs, 'msgid_plural', '')
          self.msgstr_plural = _dictget(kwargs, 'msgstr_plural', {})
          self.obsolete = _dictget(kwargs, 'obsolete', False)
          self.encoding = _dictget(kwargs, 'encoding', default_encoding)
  
      def __repr__(self):
          """Return the official string representation of the object."""
          return '<%s instance at %x>' % (self.__class__.__name__, id(self))
  
      def __str__(self, wrapwidth=78):
          """
          Common string representation of the POEntry and MOEntry
          objects.
          """
          if self.obsolete:
              delflag = '#~ '
          else:
              delflag = ''
          # write the msgid
          ret = []
          ret += self._str_field("msgid", delflag, "", self.msgid)
          # write the msgid_plural if any
          if self.msgid_plural:
              ret += self._str_field("msgid_plural", delflag, "", self.msgid_plural)
          if self.msgstr_plural:
              # write the msgstr_plural if any
              msgstrs = self.msgstr_plural
              keys = msgstrs.keys()
              keys.sort()
              for index in keys:
                  msgstr = msgstrs[index]
                  plural_index = '[%s]' % index
                  ret += self._str_field("msgstr", delflag, plural_index, msgstr)
          else:
              # otherwise write the msgstr
              ret += self._str_field("msgstr", delflag, "", self.msgstr)
          _listappend(ret, '')
          return _strjoin('\n', ret)
  
      def _str_field(self, fieldname, delflag, plural_index, field):
          field = self._decode(field)
          lines = field.splitlines(True) # keep line breaks in strings
          # potentially, we could do line-wrapping here, but textwrap.wrap
          # treats whitespace too carelessly for us to use it.
          if len(lines) > 1:
              lines = ['']+lines # start with initial empty line
          else:
              lines = [field] # needed for the empty string case
          ret = ['%s%s%s "%s"' % (delflag, fieldname, plural_index,
                                  quote(_listpop(lines, 0)))]
          for mstr in lines:
              _listappend(ret, '%s"%s"' % (delflag, quote(mstr)))
          return ret
  
      def _decode(self, st):
          if isinstance(st, unicode):
              return st.encode(self.encoding)
          return st
      # }}}
  
  
  class POEntry(_BaseEntry):
      """
      Represents a po file entry.
  
      **Examples**:
  
      >>> entry = POEntry(msgid='Welcome', msgstr='Bienvenue')
      >>> entry.occurrences = [('welcome.py', 12), ('anotherfile.py', 34)]
      >>> print entry
      #: welcome.py:12 anotherfile.py:34
      msgid "Welcome"
      msgstr "Bienvenue"
      <BLANKLINE>
      >>> entry = POEntry()
      >>> entry.occurrences = [('src/spam.c', 32), ('src/eggs.c', 45)]
      >>> entry.tcomment = 'A plural translation'
      >>> entry.flags.append('c-format')
      >>> entry.msgid = 'I have spam but no egg !'
      >>> entry.msgid_plural = 'I have spam and %d eggs !'
      >>> entry.msgstr_plural[0] = "J'ai du jambon mais aucun oeuf !"
      >>> entry.msgstr_plural[1] = "J'ai du jambon et %d oeufs !"
      >>> print entry
      # A plural translation
      #: src/spam.c:32 src/eggs.c:45
      #, c-format
      msgid "I have spam but no egg !"
      msgid_plural "I have spam and %d eggs !"
      msgstr[0] "J'ai du jambon mais aucun oeuf !"
      msgstr[1] "J'ai du jambon et %d oeufs !"
      <BLANKLINE>
      """
      # class POEntry {{{
  
      def __init__(self, *args, **kwargs):
          """POEntry constructor."""
          _BaseEntry.__init__(self, *args, **kwargs)
          self.comment = _dictget(kwargs, 'comment', '')
          self.tcomment = _dictget(kwargs, 'tcomment', '')
          self.occurrences = _dictget(kwargs, 'occurrences', [])
          self.flags = _dictget(kwargs, 'flags', [])
  
      def __str__(self, wrapwidth=78):
          """
          Return the string representation of the entry.
          """
          if self.obsolete:
              return _BaseEntry.__str__(self)
          ret = []
          # comment first, if any (with text wrapping as xgettext does)
          if self.comment != '':
              comments = _strsplit(self._decode(self.comment), '\n')
              for comment in comments:
                  if wrapwidth > 0 and len(comment) > wrapwidth-3:
                      lines = _textwrap(comment, wrapwidth,
                                        initial_indent='#. ',
                                        subsequent_indent='#. ',
                                        break_long_words=False)
                      _listappend(ret, lines)
                  else:
                      _listappend(ret, '#. %s' % comment)
          # translator comment, if any (with text wrapping as xgettext does)
          if self.tcomment != '':
              tcomments = _strsplit(self._decode(self.tcomment), '\n')
              for tcomment in tcomments:
                  if wrapwidth > 0 and len(tcomment) > wrapwidth-2:
                      lines = _textwrap(tcomment, wrapwidth,
                                        initial_indent='# ',
                                        subsequent_indent='# ',
                                        break_long_words=False)
                      _listappend(ret, lines)
                  else:
                      _listappend(ret, '# %s' % tcomment)
          # occurrences (with text wrapping as xgettext does)
          if self.occurrences:
              filelist = []
              for fpath, lineno in self.occurrences:
                  _listappend(filelist, '%s:%s' % (self._decode(fpath), lineno))
              filestr = _strjoin(' ', filelist)
              if wrapwidth > 0 and len(filestr)+3 > wrapwidth:
                  # XXX textwrap split words that contain hyphen, this is not 
                  # what we want for filenames, so the dirty hack is to 
                  # temporally replace hyphens with a char that a file cannot 
                  # contain, like "*"
                  lines = _textwrap(_strreplace(filestr, '-', '*'),
                                    wrapwidth,
                                    initial_indent='#: ',
                                    subsequent_indent='#: ',
                                    break_long_words=False)
                  # end of the replace hack
                  for line in lines:
                      _listappend(ret, _strreplace(line, '*', '-'))
              else:
                  _listappend(ret, '#: '+filestr)
          # flags
          if self.flags:
              flags = []
              for flag in self.flags:
                  _listappend(flags, flag)
              _listappend(ret, '#, %s' % _strjoin(', ', flags))
          _listappend(ret, _BaseEntry.__str__(self))
          return _strjoin('\n', ret)
  
      def __cmp__(self, other):
          '''
          Called by comparison operations if rich comparison is not defined.
  
          **Tests**:
          >>> a  = POEntry(msgid='a', occurrences=[('b.py', 1), ('b.py', 3)])
          >>> b  = POEntry(msgid='b', occurrences=[('b.py', 1), ('b.py', 3)])
          >>> c1 = POEntry(msgid='c1', occurrences=[('a.py', 1), ('b.py', 1)])
          >>> c2 = POEntry(msgid='c2', occurrences=[('a.py', 1), ('a.py', 3)])
          >>> po = POFile()
          >>> po.append(a)
          >>> po.append(b)
          >>> po.append(c1)
          >>> po.append(c2)
          >>> po.sort()
          >>> print po
          # 
          msgid ""
          msgstr ""
          <BLANKLINE>
          #: a.py:1 a.py:3
          msgid "c2"
          msgstr ""
          <BLANKLINE>
          #: a.py:1 b.py:1
          msgid "c1"
          msgstr ""
          <BLANKLINE>
          #: b.py:1 b.py:3
          msgid "a"
          msgstr ""
          <BLANKLINE>
          #: b.py:1 b.py:3
          msgid "b"
          msgstr ""
          <BLANKLINE>
          '''
          def compare_occurrences(a, b):
              """
              Compare an entry occurrence with another one.
              """
              if a[0] != b[0]:
                  return a[0] < b[0]
              if a[1] != b[1]:
                  return a[1] < b[1]
              return 0
  
          # First: Obsolete test
          if self.obsolete != other.obsolete:
              if self.obsolete:
                  return -1
              else:
                  return 1
          # Work on a copy to protect original
          occ1 = self.occurrences[:]
          occ2 = other.occurrences[:]
          # Sorting using compare method
          occ1.sort(compare_occurrences)
          occ2.sort(compare_occurrences)
          # Comparing sorted occurrences
          pos = 0
          for entry1 in occ1:
              try:
                  entry2 = occ2[pos]
              except IndexError:
                  return 1
              pos = pos + 1
              if entry1[0] != entry2[0]:
                  if entry1[0] > entry2[0]:
                      return 1
                  else:
                      return -1
              if entry1[1] != entry2[1]:
                  if entry1[1] > entry2[1]:
                      return 1
                  else:
                      return -1
          # Finally: Compare message ID
          if self.msgid > other.msgid: return 1
          else: return -1
  
      def translated(self):
          """Return True if the entry has been translated or False"""
          if self.obsolete or 'fuzzy' in self.flags:
              return False
          if self.msgstr != '':
              return True
          if self.msgstr_plural:
              for pos in self.msgstr_plural:
                  if self.msgstr_plural[pos] == '':
                      return False
              return True
          return False
  
      # }}}
  
  
  class MOEntry(_BaseEntry):
      """
      Represents a mo file entry.
  
      **Examples**:
  
      >>> entry = MOEntry()
      >>> entry.msgid  = 'translate me !'
      >>> entry.msgstr = 'traduisez moi !'
      >>> print entry
      msgid "translate me !"
      msgstr "traduisez moi !"
      <BLANKLINE>
      """
      # class MOEntry {{{
  
      def __str__(self, wrapwidth=78):
          """
          Return the string representation of the entry.
          """
          return _BaseEntry.__str__(self, wrapwidth)
      # }}}
  
  
  class _POFileParser(object):
      """
      A finite state machine to parse efficiently and correctly po
      file format.
      """
      # class _POFileParser {{{
      def __init__(self, fpath):
          """
          Constructor.
  
          **Keyword argument**:
            - *fpath*: string, path to the po file
          """
          self.fhandle = open(fpath, 'r')
          self.instance = POFile(fpath=fpath)
          self.transitions = {}
          self.current_entry = POEntry()
          self.current_state = 'ST'
          self.current_token = None
          # two memo flags used in handlers
          self.msgstr_index = 0
          self.entry_obsolete = 0
          # Configure the state machine, by adding transitions.
          # Signification of symbols:
          #     * ST: Beginning of the file (start)
          #     * HE: Header
          #     * TC: a translation comment
          #     * GC: a generated comment
          #     * OC: a file/line occurence
          #     * FL: a flags line
          #     * MI: a msgid
          #     * MP: a msgid plural
          #     * MS: a msgstr
          #     * MX: a msgstr plural
          #     * MC: a msgid or msgstr continuation line
          all_ = ['ST', 'HE', 'GC', 'OC', 'FL', 'TC', 'MS', 'MP', 'MX', 'MI']
  
          self.add('TC', ['ST', 'HE'],                                     'HE')
          self.add('TC', ['GC', 'OC', 'FL', 'TC', 'MS', 'MP', 'MX', 'MI'], 'TC')
          self.add('GC', all_,                                             'GC')
          self.add('OC', all_,                                             'OC')
          self.add('FL', all_,                                             'FL')
          self.add('MI', ['ST', 'HE', 'GC', 'OC', 'FL', 'TC', 'MS', 'MX'], 'MI')
          self.add('MP', ['TC', 'GC', 'MI'],                               'MP')
          self.add('MS', ['MI', 'MP', 'TC'],                               'MS')
          self.add('MX', ['MI', 'MX', 'MP', 'TC'],                         'MX')
          self.add('MC', ['MI', 'MP', 'MS', 'MX'],                         'MC')
  
      def parse(self):
          """
          Run the state machine, parse the file line by line and call process()
          with the current matched symbol.
          """
          i, lastlen = 1, 0
          for line in self.fhandle:
              line = _strstrip(line)
              if line == '':
                  i = i+1
                  continue
              if line[:3] == '#~ ':
                  line = line[3:]
                  self.entry_obsolete = 1
              else:
                  self.entry_obsolete = 0
              self.current_token = line
              if line[:2] == '#:':
                  # we are on a occurrences line
                  self.process('OC', i)
              elif line[:7] == 'msgid "':
                  # we are on a msgid
                  self.process('MI', i)
              elif line[:8] == 'msgstr "':
                  # we are on a msgstr
                  self.process('MS', i)
              elif line[:1] == '"':
                  # we are on a continuation line or some metadata
                  self.process('MC', i)
              elif line[:14] == 'msgid_plural "':
                  # we are on a msgid plural
                  self.process('MP', i)
              elif line[:7] == 'msgstr[':
                  # we are on a msgstr plural
                  self.process('MX', i)
              elif line[:3] == '#, ':
                  # we are on a flags line
                  self.process('FL', i)
              elif line[:2] == '# ' or line == '#':
                  if line == '#': line = line + ' '
                  # we are on a translator comment line
                  self.process('TC', i)
              elif line[:2] == '#.':
                  # we are on a generated comment line
                  self.process('GC', i)
              i = i+1
  
          if self.current_entry:
              # since entries are added when another entry is found, we must add
              # the last entry here (only if there are lines)
              _listappend(self.instance, self.current_entry)
          # before returning the instance, check if there's metadata and if 
          # so extract it in a dict
          firstentry = self.instance[0]
          if firstentry.msgid == '': # metadata found
              # remove the entry
              firstentry = _listpop(self.instance, 0)
              self.instance.metadata_is_fuzzy = firstentry.flags
              key = None
              for msg in firstentry.msgstr.splitlines():
                  try:
                      key, val = _strsplit(msg, ':', 1)
                      self.instance.metadata[key] = _strstrip(val)
                  except:
                      if key is not None:
                          self.instance.metadata[key] += '\n'+_strstrip(msg)
          # close opened file
          self.fhandle.close()
          return self.instance
  
      def add(self, symbol, states, next_state):
          """
          Add a transition to the state machine.
          Keywords arguments:
  
          symbol     -- string, the matched token (two chars symbol)
          states     -- list, a list of states (two chars symbols)
          next_state -- the next state the fsm will have after the action
          """
          for state in states:
              action = getattr(self, 'handle_%s' % next_state.lower())
              self.transitions[(symbol, state)] = (action, next_state)
  
      def process(self, symbol, linenum):
          """
          Process the transition corresponding to the current state and the
          symbol provided.
  
          Keywords arguments:
          symbol  -- string, the matched token (two chars symbol)
          linenum -- integer, the current line number of the parsed file
          """
          try:
              (action, state) = self.transitions[(symbol, self.current_state)]
              if action():
                  self.current_state = state
          except Exception, e:
              raise IOError('Syntax error in po file (line %s): %s' % \
                  (linenum, e))
  
      # state handlers
  
      def handle_he(self):
          """Handle a header comment."""
          if self.instance.header != '':
              self.instance.header += '\n'
          self.instance.header += self.current_token[2:]
          return 1
  
      def handle_tc(self):
          """Handle a translator comment."""
          if self.current_state in ['MC', 'MS', 'MX']:
              _listappend(self.instance, self.current_entry)
              self.current_entry = POEntry()
          if self.current_entry.tcomment != '':
              self.current_entry.tcomment += '\n'
          self.current_entry.tcomment += self.current_token[2:]
          return True
  
      def handle_gc(self):
          """Handle a generated comment."""
          if self.current_state in ['MC', 'MS', 'MX']:
              _listappend(self.instance, self.current_entry)
              self.current_entry = POEntry()
          if self.current_entry.comment != '':
              self.current_entry.comment += '\n'
          self.current_entry.comment += self.current_token[3:]
          return True
  
      def handle_oc(self):
          """Handle a file:num occurence."""
          if self.current_state in ['MC', 'MS', 'MX']:
              _listappend(self.instance, self.current_entry)
              self.current_entry = POEntry()
          occurrences = _strsplit(self.current_token[3:])
          for occurrence in occurrences:
              if occurrence != '':
                  fil, line = _strsplit(occurrence, ':')
                  _listappend(self.current_entry.occurrences, (fil, line))
          return True
  
      def handle_fl(self):
          """Handle a flags line."""
          if self.current_state in ['MC', 'MS', 'MX']:
              _listappend(self.instance, self.current_entry)
              self.current_entry = POEntry()
          self.current_entry.flags += _strsplit(self.current_token[3:], ', ')
          return True
  
      def handle_mi(self):
          """Handle a msgid."""
          if self.current_state in ['MC', 'MS', 'MX']:
              _listappend(self.instance, self.current_entry)
              self.current_entry = POEntry()
          self.current_entry.obsolete = self.entry_obsolete
          self.current_entry.msgid = unquote(self.current_token[7:-1])
          return True
  
      def handle_mp(self):
          """Handle a msgid plural."""
          self.current_entry.msgid_plural = unquote(self.current_token[14:-1])
          return True
  
      def handle_ms(self):
          """Handle a msgstr."""
          self.current_entry.msgstr = unquote(self.current_token[8:-1])
          return True
  
      def handle_mx(self):
          """Handle a msgstr plural."""
          index, value = self.current_token[7], self.current_token[11:-1]
          self.current_entry.msgstr_plural[index] = unquote(value)
          self.msgstr_index = index
          return True
  
      def handle_mc(self):
          """Handle a msgid or msgstr continuation line."""
          if self.current_state == 'MI':
              self.current_entry.msgid += unquote(self.current_token[1:-1])
          elif self.current_state == 'MP':
              self.current_entry.msgid_plural += \
                  unquote(self.current_token[1:-1])
          elif self.current_state == 'MS':
              self.current_entry.msgstr += unquote(self.current_token[1:-1])
          elif self.current_state == 'MX':
              msgstr = self.current_entry.msgstr_plural[self.msgstr_index] +\
                  unquote(self.current_token[1:-1])
              self.current_entry.msgstr_plural[self.msgstr_index] = msgstr
          # don't change the current state
          return False
      # }}}
  
  
  class _MOFileParser(object):
      """
      A class to parse binary mo files.
      """
      # class _MOFileParser {{{
      def __init__(self, fpath):
          """_MOFileParser constructor."""
          self.fhandle = open(fpath, 'rb')
          self.instance = MOFile(fpath)
  
      def parse_magicnumber(self):
          """
          Parse the magic number and raise an exception if not valid.
          """
          magic_number = self._readbinary(fmt='4s')
          # magic number must be 0xde120495 or 0x950412de
          if magic_number not in ['\xde\x12\x04\x95', '\x95\x04\x12\xde']:
              raise IOError('Invalid mo file, magic number is incorrect !')
          self.instance.magic_number = magic_number
  
      def parse(self):
          """
          Build the instance with the file handle provided in the
          constructor.
          """
          self.parse_magicnumber()
          # parse the version number
          self.instance.version = self._readbinary('L')
          # parse the number of strings
          numofstrings = self._readbinary('L')
          # original strings hash table offset
          msgids_hash_offset = self._readbinary('L')
          # translation strings hash table offset
          msgstrs_hash_offset = self._readbinary('P')
          # move to msgid hash table and read length and offset of msgids
          self.fhandle.seek(msgids_hash_offset)
          msgids_index = []
          for i in range(numofstrings):
              _listappend(msgids_index, self._readbinary('LL'))
          # move to msgstr hash table and read length and offset of msgstrs
          self.fhandle.seek(msgstrs_hash_offset)
          msgstrs_index = []
          for i in range(numofstrings):
              _listappend(msgstrs_index, self._readbinary('LL'))
          # build entries
          for i in range(numofstrings):
              self.fhandle.seek(msgids_index[i][1])
              msgid = self.fhandle.read(msgids_index[i][0])
              self.fhandle.seek(msgstrs_index[i][1])
              msgstr = self.fhandle.read(msgstrs_index[i][0])
              if i == 0: # metadata
                  raw_metadata, metadata = _strsplit(msgstr, '\n'), {}
                  for line in raw_metadata:
                      tokens = _strsplit(line, ':', 1)
                      if tokens[0] != '':
                          try:
                              metadata[tokens[0]] = _strstrip(tokens[1])
                          except IndexError:
                              metadata[tokens[0]] = ''
                  self.instance.metadata = metadata
                  continue
              entry = MOEntry(msgid=msgid, msgstr=msgstr)
              _listappend(self.instance, entry)
          # close opened file
          self.fhandle.close()
          return self.instance
  
      def _readbinary(self, fmt='c'):
          """
          Private method that unpack n bytes of data using format <fmt>.
          It returns a tuple or a mixed value if the tuple length is 1.
          """
          numbytes = struct.calcsize(fmt)
          bytes = self.fhandle.read(numbytes)
          tup = struct.unpack(fmt, bytes)
          if len(tup) == 1:
              return tup[0]
          return tup
      # }}}
  
  
  if __name__ == '__main__':
      """
      **Main function**::
        - to **test** the module just run: *python polib.py [-v]*
        - to **profile** the module: *python polib.py -p <some_pofile.po>*
      """
      # main function {{{
      import sys
      if len(sys.argv) > 2 and sys.argv[1] == '-p':
          def test(f):
              if f.endswith('po'):
                  p = pofile(f)
              else:
                  p = mofile(f)
              s = str(p)
          import profile
          profile.run('test("'+sys.argv[2]+'")')
      else:
          import doctest
          doctest.testmod()
      # }}}
  
  