i18n_template.py

#!/usr/bin/python
#vim:set fileencoding=utf-8 sw=2

#
# Remove unused catalog text lines from ".po" file.
#

template = 'Resources_en.po'

def unquote(s):
  s = s.strip()
  if s[0] != '"' or s[-1] != '"':
    raise RuntimeError
  return s[1:-1]

def read_po(fp):
  st = 1
  comment = key = value = rkey = rvalue = ''
  for line in fp:
    if line[0] == '#' or line.strip() == '':
      if st == 2:
	yield (comment, key, value, rkey, rvalue)
	st = 1
	comment = key = value = rkey = rvalue = ''
      comment += line
    elif line[0] == '"':
      if st == 1:
	key += unquote(line)
	rkey += line
      else:
	value += unquote(line)
	rvalue += line
    elif line.startswith('msgid '):
      st = 1
      key = unquote(line[5:])
      rkey = line
    elif line.startswith('msgstr '):
      st = 2
      value = unquote(line[6:])
      rvalue = line
    else:
      raise RuntimeError

  if st == 2:
    yield (comment, key, value, rkey, rvalue)

def process(target):
  # Read the current text catalog.
  d = {}
  firstcomment = ''
  it = read_po(file(target))
  try:
    (comment, key, value, rkey, rvalue) = it.next()
    d[key] = rvalue
    firstcomment = comment		# Preserve the first comment block
  except StopIteration:
    pass
  for (comment, key, value, rkey, rvalue) in it:
    d[key] = rvalue

  # Read the template text catalog and output.
  # The translated values come from the current text catalog read above.
  out = file(target, 'w')
  out.write(firstcomment)
  it = read_po(file(template))
  try:
    (comment, key, value, rkey, rvalue) = it.next()
    out.write(rkey)
    out.write(d.get(key, rvalue))
  except StopIteration:
    pass
  for (comment, key, value, rkey, rvalue) in it:
    out.write(comment)
    out.write(rkey)
    out.write(d.get(key, rvalue))

def main():
  import sys
  for f in sys.argv[1:]:
    if f == template:
      continue
    print 'Update %s...' % f
    process(f)

if __name__ == '__main__':
  main()