cnpython/Lib/gettext.py at cnpython · lp9102/cnpython · GitHub

History

650 lines (568 loc) · 21.5 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

"""Internationalization and localization support.

This module provides internationalization (I18N) and localization (L10N)

support for your Python programs by providing an interface to the GNU gettext

message catalog library.

I18N refers to the operation by which a program is made aware of multiple

languages. L10N refers to the adaptation of your program, once

internationalized, to the local language and cultural habits.

"""

# This module represents the integration of work, contributions, feedback, and

# suggestions from the following people:

# Martin von Loewis, who wrote the initial implementation of the underlying

# C-based libintlmodule (later renamed _gettext), along with a skeletal

# gettext.py implementation.

# Peter Funk, who wrote fintl.py, a fairly complete wrapper around intlmodule,

# which also included a pure-Python implementation to read .mo files if

# intlmodule wasn't available.

# James Henstridge, who also wrote a gettext.py module, which has some

# interesting, but currently unsupported experimental features: the notion of

# a Catalog class and instances, and the ability to add to a catalog file via

# a Python API.

# Barry Warsaw integrated these modules, wrote the .install() API and code,

# and conformed all C and Python code to Python's coding standards.

# Francois Pinard and Marc-Andre Lemburg also contributed valuably to this

# module.

# J. David Ibanez implemented plural forms. Bruno Haible fixed some bugs.

# TODO:

# - Lazy loading of .mo files. Currently the entire catalog is loaded into

# memory, but that's probably bad for large translated programs. Instead,

# the lexical sort of original strings in GNU .mo files should be exploited

# to do binary searches and lazy initializations. Or you might want to use

# the undocumented double-hash algorithm for .mo files with hash tables, but

# you'll need to study the GNU gettext code to do this.

# - Support Solaris .mo file formats. Unfortunately, we've been unable to

# find this format documented anywhere.

import locale

import os

import re

import sys

__all__ = ['NullTranslations', 'GNUTranslations', 'Catalog',

'find', 'translation', 'install', 'textdomain', 'bindtextdomain',

'bind_textdomain_codeset',

'dgettext', 'dngettext', 'gettext', 'lgettext', 'ldgettext',

'ldngettext', 'lngettext', 'ngettext',

]

_default_localedir = os.path.join(sys.base_prefix, 'share', 'locale')

# Expression parsing for plural form selection.

# The gettext library supports a small subset of C syntax. The only

# incompatible difference is that integer literals starting with zero are

# decimal.

# https://www.gnu.org/software/gettext/manual/gettext.html#Plural-forms

# http://git.savannah.gnu.org/cgit/gettext.git/tree/gettext-runtime/intl/plural.y

_token_pattern = re.compile(r"""

(?P<WHITESPACES>[ \t]+) | # spaces and horizontal tabs

(?P<NUMBER>[0-9]+\b) | # decimal integer

(?P<NAME>n\b) | # only n is allowed

(?P<PARENTHESIS>[()]) |

(?P<OPERATOR>[-*/%+?:]|[><!]=?|==|&&|\|\|) | # !, *, /, %, +, -, <, >,

# <=, >=, ==, !=, &&, ||,

# ? :

# unary and bitwise ops

# not allowed

(?P<INVALID>\w+|.) # invalid token

""", re.VERBOSE|re.DOTALL)

def _tokenize(plural):

for mo in re.finditer(_token_pattern, plural):

kind = mo.lastgroup

if kind == 'WHITESPACES':

continue

value = mo.group(kind)

if kind == 'INVALID':

raise ValueError('invalid token in plural form: %s' % value)

yield value

yield ''

def _error(value):

if value:

return ValueError('unexpected token in plural form: %s' % value)

else:

return ValueError('unexpected end of plural form')

_binary_ops = (

('||',),

('&&',),

('==', '!='),

('<', '>', '<=', '>='),

('+', '-'),

('*', '/', '%'),

)

_binary_ops = {op: i for i, ops in enumerate(_binary_ops, 1) for op in ops}

_c2py_ops = {'||': 'or', '&&': 'and', '/': '//'}

def _parse(tokens, priority=-1):

result = ''

nexttok = next(tokens)

while nexttok == '!':

result += 'not '

nexttok = next(tokens)

if nexttok == '(':

sub, nexttok = _parse(tokens)

result = '%s(%s)' % (result, sub)

if nexttok != ')':

raise ValueError('unbalanced parenthesis in plural form')

elif nexttok == 'n':

result = '%s%s' % (result, nexttok)

else:

try:

value = int(nexttok, 10)

except ValueError:

raise _error(nexttok) from None

result = '%s%d' % (result, value)

nexttok = next(tokens)

j = 100

while nexttok in _binary_ops:

i = _binary_ops[nexttok]

if i < priority:

break

# Break chained comparisons

if i in (3, 4) and j in (3, 4): # '==', '!=', '<', '>', '<=', '>='

result = '(%s)' % result

# Replace some C operators by their Python equivalents

op = _c2py_ops.get(nexttok, nexttok)

right, nexttok = _parse(tokens, i + 1)

result = '%s %s %s' % (result, op, right)

j = i

if j == priority == 4: # '<', '>', '<=', '>='

result = '(%s)' % result

if nexttok == '?' and priority <= 0:

if_true, nexttok = _parse(tokens, 0)

if nexttok != ':':

raise _error(nexttok)

if_false, nexttok = _parse(tokens)

result = '%s if %s else %s' % (if_true, result, if_false)

if priority == 0:

result = '(%s)' % result

return result, nexttok

def _as_int(n):

try:

i = round(n)

except TypeError:

raise TypeError('Plural value must be an integer, got %s' %

(n.__class__.__name__,)) from None

import warnings

warnings.warn('Plural value must be an integer, got %s' %

(n.__class__.__name__,),

DeprecationWarning, 4)

return n

def c2py(plural):

"""Gets a C expression as used in PO files for plural forms and returns a

Python function that implements an equivalent expression.

"""

if len(plural) > 1000:

raise ValueError('plural form expression is too long')

try:

result, nexttok = _parse(_tokenize(plural))

if nexttok:

raise _error(nexttok)

depth = 0

for c in result:

if c == '(':

depth += 1

if depth > 20:

# Python compiler limit is about 90.

# The most complex example has 2.

raise ValueError('plural form expression is too complex')

elif c == ')':

depth -= 1

ns = {'_as_int': _as_int}

exec('''if True:

def func(n):

if not isinstance(n, int):

n = _as_int(n)

return int(%s)

''' % result, ns)

return ns['func']

except RecursionError:

# Recursion error can be raised in _parse() or exec().

raise ValueError('plural form expression is too complex')

def _expand_lang(loc):

loc = locale.normalize(loc)

COMPONENT_CODESET = 1 << 0

COMPONENT_TERRITORY = 1 << 1

COMPONENT_MODIFIER = 1 << 2

# split up the locale into its base components

mask = 0

pos = loc.find('@')

if pos >= 0:

modifier = loc[pos:]

loc = loc[:pos]

mask |= COMPONENT_MODIFIER

else:

modifier = ''

pos = loc.find('.')

if pos >= 0:

codeset = loc[pos:]

loc = loc[:pos]

mask |= COMPONENT_CODESET

else:

codeset = ''

pos = loc.find('_')

if pos >= 0:

territory = loc[pos:]

loc = loc[:pos]

mask |= COMPONENT_TERRITORY

else:

territory = ''

language = loc

ret = []

for i in range(mask+1):

if not (i & ~mask): # if all components for this combo exist ...

val = language

if i & COMPONENT_TERRITORY: val += territory

if i & COMPONENT_CODESET: val += codeset

if i & COMPONENT_MODIFIER: val += modifier

ret.append(val)

ret.reverse()

return ret

class NullTranslations:

def __init__(self, fp=None):

self._info = {}

self._charset = None

self._output_charset = None

self._fallback = None

if fp is not None:

self._parse(fp)

def _parse(self, fp):

pass

def add_fallback(self, fallback):

if self._fallback:

self._fallback.add_fallback(fallback)

else:

self._fallback = fallback

def gettext(self, message):

if self._fallback:

return self._fallback.gettext(message)

return message

def lgettext(self, message):

if self._fallback:

return self._fallback.lgettext(message)

if self._output_charset:

return message.encode(self._output_charset)

return message.encode(locale.getpreferredencoding())

def ngettext(self, msgid1, msgid2, n):

if self._fallback:

return self._fallback.ngettext(msgid1, msgid2, n)

if n == 1:

return msgid1

else:

return msgid2

def lngettext(self, msgid1, msgid2, n):

if self._fallback:

return self._fallback.lngettext(msgid1, msgid2, n)

if n == 1:

tmsg = msgid1

else:

tmsg = msgid2

if self._output_charset:

return tmsg.encode(self._output_charset)

return tmsg.encode(locale.getpreferredencoding())

def info(self):

return self._info

def charset(self):

return self._charset

def output_charset(self):

return self._output_charset

def set_output_charset(self, charset):

self._output_charset = charset

def install(self, names=None):

import builtins

builtins.__dict__['_'] = self.gettext

if hasattr(names, "__contains__"):

if "gettext" in names:

builtins.__dict__['gettext'] = builtins.__dict__['_']

if "ngettext" in names:

builtins.__dict__['ngettext'] = self.ngettext

if "lgettext" in names:

builtins.__dict__['lgettext'] = self.lgettext

if "lngettext" in names:

builtins.__dict__['lngettext'] = self.lngettext

class GNUTranslations(NullTranslations):

# Magic number of .mo files

LE_MAGIC = 0x950412de

BE_MAGIC = 0xde120495

# Acceptable .mo versions

VERSIONS = (0, 1)

def _get_versions(self, version):

"""Returns a tuple of major version, minor version"""

return (version >> 16, version & 0xffff)

def _parse(self, fp):

"""Override this method to support alternative .mo formats."""

# Delay struct import for speeding up gettext import when .mo files

# are not used.

from struct import unpack

filename = getattr(fp, 'name', '')

# Parse the .mo file header, which consists of 5 little endian 32

# bit words.

self._catalog = catalog = {}

self.plural = lambda n: int(n != 1) # germanic plural by default

buf = fp.read()

buflen = len(buf)

# Are we big endian or little endian?

magic = unpack('<I', buf[:4])[0]

if magic == self.LE_MAGIC:

version, msgcount, masteridx, transidx = unpack('<4I', buf[4:20])

ii = '<II'

elif magic == self.BE_MAGIC:

version, msgcount, masteridx, transidx = unpack('>4I', buf[4:20])

ii = '>II'

else:

raise OSError(0, 'Bad magic number', filename)

major_version, minor_version = self._get_versions(version)

if major_version not in self.VERSIONS:

raise OSError(0, 'Bad version number ' + str(major_version), filename)

# Now put all messages from the .mo file buffer into the catalog

# dictionary.

for i in range(0, msgcount):

mlen, moff = unpack(ii, buf[masteridx:masteridx+8])

mend = moff + mlen

tlen, toff = unpack(ii, buf[transidx:transidx+8])

tend = toff + tlen

if mend < buflen and tend < buflen:

msg = buf[moff:mend]

tmsg = buf[toff:tend]

else:

raise OSError(0, 'File is corrupt', filename)

# See if we're looking at GNU .mo conventions for metadata

if mlen == 0:

# Catalog description

lastk = None

for b_item in tmsg.split(b'\n'):

item = b_item.decode().strip()

if not item:

continue

k = v = None

if ':' in item:

k, v = item.split(':', 1)

k = k.strip().lower()

v = v.strip()

self._info[k] = v

lastk = k

elif lastk:

self._info[lastk] += '\n' + item

if k == 'content-type':

self._charset = v.split('charset=')[1]

elif k == 'plural-forms':

v = v.split(';')

plural = v[1].split('plural=')[1]

self.plural = c2py(plural)

# Note: we unconditionally convert both msgids and msgstrs to

# Unicode using the character encoding specified in the charset

# parameter of the Content-Type header. The gettext documentation

# strongly encourages msgids to be us-ascii, but some applications

# require alternative encodings (e.g. Zope's ZCML and ZPT). For

# traditional gettext applications, the msgid conversion will

# cause no problems since us-ascii should always be a subset of

# the charset encoding. We may want to fall back to 8-bit msgids

# if the Unicode conversion fails.

charset = self._charset or 'ascii'

if b'\x00' in msg:

# Plural forms

msgid1, msgid2 = msg.split(b'\x00')

tmsg = tmsg.split(b'\x00')

msgid1 = str(msgid1, charset)

for i, x in enumerate(tmsg):

catalog[(msgid1, i)] = str(x, charset)

else:

catalog[str(msg, charset)] = str(tmsg, charset)

# advance to next entry in the seek tables

masteridx += 8

transidx += 8

def lgettext(self, message):

missing = object()

tmsg = self._catalog.get(message, missing)

if tmsg is missing:

if self._fallback:

return self._fallback.lgettext(message)

tmsg = message

if self._output_charset:

return tmsg.encode(self._output_charset)

return tmsg.encode(locale.getpreferredencoding())

def lngettext(self, msgid1, msgid2, n):

try:

tmsg = self._catalog[(msgid1, self.plural(n))]

except KeyError:

if self._fallback:

return self._fallback.lngettext(msgid1, msgid2, n)

if n == 1:

tmsg = msgid1

else:

tmsg = msgid2

if self._output_charset:

return tmsg.encode(self._output_charset)

return tmsg.encode(locale.getpreferredencoding())

def gettext(self, message):

missing = object()

tmsg = self._catalog.get(message, missing)

if tmsg is missing:

if self._fallback:

return self._fallback.gettext(message)

return message

return tmsg

def ngettext(self, msgid1, msgid2, n):

try:

tmsg = self._catalog[(msgid1, self.plural(n))]

except KeyError:

if self._fallback:

return self._fallback.ngettext(msgid1, msgid2, n)

if n == 1:

tmsg = msgid1

else:

tmsg = msgid2

return tmsg

# Locate a .mo file using the gettext strategy

def find(domain, localedir=None, languages=None, all=False):

# Get some reasonable defaults for arguments that were not supplied

if localedir is None:

localedir = _default_localedir

if languages is None:

languages = []

for envar in ('LANGUAGE', 'LC_ALL', 'LC_MESSAGES', 'LANG'):

val = os.environ.get(envar)

if val:

languages = val.split(':')

break

if 'C' not in languages:

languages.append('C')

# now normalize and expand the languages

nelangs = []

for lang in languages:

for nelang in _expand_lang(lang):

if nelang not in nelangs:

nelangs.append(nelang)

# select a language

if all:

result = []

else:

result = None

for lang in nelangs:

if lang == 'C':

break

mofile = os.path.join(localedir, lang, 'LC_MESSAGES', '%s.mo' % domain)

if os.path.exists(mofile):

if all:

result.append(mofile)

else:

return mofile

return result

# a mapping between absolute .mo file path and Translation object

_translations = {}

def translation(domain, localedir=None, languages=None,

class_=None, fallback=False, codeset=None):

if class_ is None:

class_ = GNUTranslations

mofiles = find(domain, localedir, languages, all=True)

if not mofiles:

if fallback:

return NullTranslations()

from errno import ENOENT

raise FileNotFoundError(ENOENT,

'No translation file found for domain', domain)

# Avoid opening, reading, and parsing the .mo file after it's been done

# once.

result = None

for mofile in mofiles:

key = (class_, os.path.abspath(mofile))

t = _translations.get(key)

if t is None:

with open(mofile, 'rb') as fp:

t = _translations.setdefault(key, class_(fp))

# Copy the translation object to allow setting fallbacks and

# output charset. All other instance data is shared with the

# cached object.

# Delay copy import for speeding up gettext import when .mo files

# are not used.

import copy

t = copy.copy(t)

if codeset:

t.set_output_charset(codeset)

if result is None:

result = t

else:

result.add_fallback(t)

return result

def install(domain, localedir=None, codeset=None, names=None):

t = translation(domain, localedir, fallback=True, codeset=codeset)

t.install(names)

# a mapping b/w domains and locale directories

_localedirs = {}

# a mapping b/w domains and codesets

_localecodesets = {}

# current global domain, `messages' used for compatibility w/ GNU gettext

_current_domain = 'messages'

def textdomain(domain=None):

global _current_domain

if domain is not None:

_current_domain = domain

return _current_domain

def bindtextdomain(domain, localedir=None):

global _localedirs

if localedir is not None:

_localedirs[domain] = localedir

return _localedirs.get(domain, _default_localedir)

def bind_textdomain_codeset(domain, codeset=None):

global _localecodesets

if codeset is not None:

_localecodesets[domain] = codeset

return _localecodesets.get(domain)

def dgettext(domain, message):

try:

t = translation(domain, _localedirs.get(domain, None),

codeset=_localecodesets.get(domain))

except OSError:

return message

return t.gettext(message)

def ldgettext(domain, message):

codeset = _localecodesets.get(domain)

try:

t = translation(domain, _localedirs.get(domain, None), codeset=codeset)

except OSError:

return message.encode(codeset or locale.getpreferredencoding())

return t.lgettext(message)

def dngettext(domain, msgid1, msgid2, n):

try:

t = translation(domain, _localedirs.get(domain, None),

codeset=_localecodesets.get(domain))

except OSError:

if n == 1:

return msgid1

else:

return msgid2

return t.ngettext(msgid1, msgid2, n)

def ldngettext(domain, msgid1, msgid2, n):

codeset = _localecodesets.get(domain)

try:

t = translation(domain, _localedirs.get(domain, None), codeset=codeset)

except OSError:

if n == 1:

tmsg = msgid1

else:

tmsg = msgid2

return tmsg.encode(codeset or locale.getpreferredencoding())

return t.lngettext(msgid1, msgid2, n)

def gettext(message):

return dgettext(_current_domain, message)

def lgettext(message):

return ldgettext(_current_domain, message)

def ngettext(msgid1, msgid2, n):

return dngettext(_current_domain, msgid1, msgid2, n)

def lngettext(msgid1, msgid2, n):

return ldngettext(_current_domain, msgid1, msgid2, n)

# dcgettext() has been deemed unnecessary and is not implemented.

# James Henstridge's Catalog constructor from GNOME gettext. Documented usage

# was:

# import gettext

# cat = gettext.Catalog(PACKAGE, localedir=LOCALEDIR)

# _ = cat.gettext

# print _('Hello World')

# The resulting catalog object currently don't support access through a

# dictionary API, which was supported (but apparently unused) in GNOME

# gettext.

Catalog = translation

cnpython/Lib/gettext.py at cnpython · lp9102/cnpython · GitHub

Expand file tree

Breadcrumbs

gettext.py

Latest commit

History

Breadcrumbs

gettext.py

File metadata and controls