test.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

translation_to = 'fr'

import sys  
reload(sys)  
sys.setdefaultencoding('utf8')

import codecs
import json
import requests

def translate(s):
    try:
        r = requests.get('http://api.mymemory.translated.net/get?q=%s&langpair=en|%s' % (s, translation_to), timeout=6)
    except requests.exceptions.ReadTimeout, e:
        print >> sys.stderr, type(e), e
        return ""
        
    j = json.loads(r.text)
    reply = j['responseData']['translatedText']
    if reply is None:
        print >> sys.stderr, r.text
        return ""

    for k in ['INVALID LANGUAGE PAIR SPECIFIED.', 'NO QUERY SPECIFIED', 'QUERY LENGTH LIMIT EXCEDEED', 'MYMEMORY WARNING:']:
        if reply.startswith(k):
            print >> sys.stderr, reply
            return ""
    return reply

with codecs.open("po/%s.po" % translation_to) as f:
    defining = None
    msgdef = {'msgid': '', 'msgstr': ''}
    complete = {'msgid': '', 'msgstr': ''}
    lines = f.readlines()
    for n, l in enumerate(lines):
        l = l.strip()
        if not l:
            defining = None
            if not msgdef['msgstr'] and msgdef['msgid'].find(' ') != -1:
                msgdef['msgstr'] = translate(msgdef['msgid'])
                complete['msgstr'] = u'msgstr "%s"\n' % msgdef['msgstr']
            print '%(msgid)s%(msgstr)s' % complete
            continue
        if l[0] == '#':
            print l
            continue
        if l.startswith('msgid'):
            msgdef = {'msgid': '', 'msgstr': ''}
            complete = {'msgid': '', 'msgstr': ''}
            defining = 'msgid'
            complete[defining] += l + '\n'
            l = l[6:]
            msgdef[defining] += l[1:-1]
            continue
        if l.startswith('msgstr'):
            defining = 'msgstr'
            complete[defining] += l + '\n'
            l = l[7:]
            msgdef[defining] += l[1:-1]
            continue
        if defining:
            msgdef[defining] += l[1:-1]
            complete[defining] += l + '\n'

print '%(msgid)s%(msgstr)s' % complete