#! /usr/bin/env python """pygettext -- Python equivalent of xgettext(1) Many systems (Solaris, Linux, Gnu) provide extensive tools that ease the internationalization of C programs. Most of these tools are independent of the programming language and can be used from within Python programs. Martin von Loewis' work[1] helps considerably in this regard. There's one hole though; xgettext is the program that scans source code looking for message strings, but it groks only C (or C++). Python introduces a few wrinkles, such as dual quoting characters, triple quoted strings, and raw strings. xgettext understands none of this. Enter pygettext, which uses Python's standard tokenize module to scan Python source code, generating .pot files identical to what GNU xgettext[2] generates for C and C++ code. From there, the standard GNU tools can be used. A word about marking Python strings as candidates for translation. GNU xgettext recognizes the following keywords: gettext, dgettext, dcgettext, and gettext_noop. But those can be a lot of text to include all over your code. C and C++ have a trick: they use the C preprocessor. Most internationalized C source includes a #define for gettext() to _() so that what has to be written in the source is much less. Thus these are both translatable strings: gettext("Translatable String") _("Translatable String") Python of course has no preprocessor so this doesn't work so well. Thus, pygettext searches only for _() by default, but see the -k/--keyword flag below for how to augment this. [1] http://www.python.org/workshops/1997-10/proceedings/loewis.html [2] http://www.gnu.org/software/gettext/gettext.html NOTE: pygettext attempts to be option and feature compatible with GNU xgettext where ever possible. Usage: pygettext [options] filename ... Options: -a --extract-all Extract all strings -d default-domain --default-domain=default-domain Rename the default output file from messages.pot to default-domain.pot -k [word] --keyword[=word] Additional keywords to look for. Without `word' means not to use the default keywords. The default keywords, which are always looked for if not explicitly disabled: _ The default keyword list is different than GNU xgettext. You can have multiple -k flags on the command line. --no-location Do not write filename/lineno location comments -n [style] --add-location[=style] Write filename/lineno location comments indicating where each extracted string is found in the source. These lines appear before each msgid. Two styles are supported: Solaris # File: filename, line: line-number Gnu #: filename:line If style is omitted, Gnu is used. The style name is case insensitive. By default, locations are included. --help -h print this help message and exit """ import os import sys import string import time import getopt import tokenize __version__ = '0.1' def usage(code, msg=''): print __doc__ % globals() if msg: print msg sys.exit(code) def normalize(s): # This converts the various Python string types into a format that is # appropriate for .po files, namely much closer to C style. # # unwrap quotes, safely s = eval(s, {'__builtins__':{}}, {}) # now escape any embedded double quotes parts = [] last = 0 i = string.find(s, '"') while i >= 0: # find the number of preceding backslashes j = i n = 0 while j >= 0 and s[i] == '\\': j = j - 1 n = n + 1 if (n % 2) == 0: parts.append(s[last:j]) parts.append('\\') parts.append(s[j:i]) else: parts.append(s[last:i]) last = i i = string.find(s, '"', i+1) else: parts.append(s[last:]) if parts: return '"' + string.join(parts, '') + '"' else: return '"' + s + '"' class TokenEater: def __init__(self, options): self.__options = options self.__messages = {} self.__state = self.__waiting self.__data = [] self.__lineno = -1 def __call__(self, ttype, tstring, stup, etup, line): # dispatch self.__state(ttype, tstring, stup[0]) def __waiting(self, ttype, tstring, lineno): if ttype == tokenize.NAME and tstring in self.__options.keywords: self.__state = self.__keywordseen def __keywordseen(self, ttype, tstring, lineno): if ttype == tokenize.OP and tstring == '(': self.__data = [] self.__lineno = lineno self.__state = self.__openseen else: self.__state = self.__waiting def __openseen(self, ttype, tstring, lineno): if ttype == tokenize.OP and tstring == ')': # We've seen the last of the translatable strings. Record the # line number of the first line of the strings and update the list # of messages seen. Reset state for the next batch. If there # were no strings inside _(), then just ignore this entry. if self.__data: msg = string.join(self.__data, '') entry = (self.__curfile, self.__lineno) linenos = self.__messages.get(msg) if linenos is None: self.__messages[msg] = [entry] else: linenos.append(entry) self.__state = self.__waiting elif ttype == tokenize.STRING: self.__data.append(normalize(tstring)) # TBD: should we warn if we seen anything else? def set_filename(self, filename): self.__curfile = filename def write(self, fp): options = self.__options timestamp = time.ctime(time.time()) # common header try: sys.stdout = fp print '# POT file generated by pygettext.py', __version__ print '#', timestamp print '#' for k, v in self.__messages.items(): for filename, lineno in v: # location comments are different b/w Solaris and GNU if options.location == options.SOLARIS: print '# File: %s,' % filename, 'line: %d' % lineno elif options.location == options.GNU: print '#: %s:%d' % (filename, lineno) # TBD: sorting, normalizing print 'msgid', k print 'msgstr ' print finally: sys.stdout = sys.__stdout__ def main(): default_keywords = ['i18n'] # was '_' try: opts, args = getopt.getopt( sys.argv[1:], 'k:d:n:h', ['keyword', 'default-domain', 'help', 'add-location=', 'no-location']) except getopt.error, msg: usage(1, msg) # for holding option values class Options: # constants GNU = 1 SOLARIS = 2 # defaults keywords = [] outfile = 'messages.pot' location = GNU options = Options() locations = {'gnu' : options.GNU, 'solaris' : options.SOLARIS, } # parse options for opt, arg in opts: if opt in ('-h', '--help'): usage(0) elif opt in ('-k', '--keyword'): if arg is None: default_keywords = [] options.keywords.append(arg) elif opt in ('-d', '--default-domain'): options.outfile = arg + '.pot' elif opt in ('-n', '--add-location'): if arg is None: arg = 'gnu' try: options.location = locations[string.lower(arg)] except KeyError: usage(1, 'Invalid value for --add-location: ' + arg) elif opt in ('--no-location',): options.location = 0 # calculate all keywords options.keywords.extend(default_keywords) # slurp through all the files eater = TokenEater(options) for filename in args: fp = open(filename) eater.set_filename(filename) tokenize.tokenize(fp.readline, eater) fp.close() fp = open(options.outfile, 'w') eater.write(fp) fp.close() if __name__ == '__main__': main()