cpython/Lib/argparse.py at 8e7586bd44cf2a117228bb8d2b2de52ae1e88fab · python/cpython · GitHub

Repository navigation

History

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

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

# Author: Steven J. Bethard <steven.bethard@gmail.com>.

"""Command-line parsing library

This module is an optparse-inspired command-line parsing library that:

- handles both optional and positional arguments

- produces highly informative usage messages

- supports parsers that dispatch to sub-parsers

The following is a simple usage example that sums integers from the

command-line and writes the result to a file::

parser = argparse.ArgumentParser(

description='sum the integers at the command line')

parser.add_argument(

'integers', metavar='int', nargs='+', type=int,

help='an integer to be summed')

parser.add_argument(

'--log', default=sys.stdout, type=argparse.FileType('w'),

help='the file where the sum should be written')

args = parser.parse_args()

args.log.write('%s' % sum(args.integers))

args.log.close()

The module contains the following public classes:

- ArgumentParser -- The main entry point for command-line parsing. As the

example above shows, the add_argument() method is used to populate

the parser with actions for optional and positional arguments. Then

the parse_args() method is invoked to convert the args at the

command-line into an object with attributes.

- ArgumentError -- The exception raised by ArgumentParser objects when

there are errors with the parser's actions. Errors raised while

parsing the command-line are caught by ArgumentParser and emitted

as command-line messages.

- FileType -- A factory for defining types of files to be created. As the

example above shows, instances of FileType are typically passed as

the type= argument of add_argument() calls.

- Action -- The base class for parser actions. Typically actions are

selected by passing strings like 'store_true' or 'append_const' to

the action= argument of add_argument(). However, for greater

customization of ArgumentParser actions, subclasses of Action may

be defined and passed as the action= argument.

- HelpFormatter, RawDescriptionHelpFormatter, RawTextHelpFormatter,

ArgumentDefaultsHelpFormatter -- Formatter classes which

may be passed as the formatter_class= argument to the

ArgumentParser constructor. HelpFormatter is the default,

RawDescriptionHelpFormatter and RawTextHelpFormatter tell the parser

not to change the formatting for help text, and

ArgumentDefaultsHelpFormatter adds information about argument defaults

to the help.

All other classes in this module are considered implementation details.

(Also note that HelpFormatter and RawDescriptionHelpFormatter are only

considered public as object names -- the API of the formatter objects is

still considered an implementation detail.)

"""

__version__ = '1.1'

__all__ = [

'ArgumentParser',

'ArgumentError',

'ArgumentTypeError',

'FileType',

'HelpFormatter',

'ArgumentDefaultsHelpFormatter',

'RawDescriptionHelpFormatter',

'RawTextHelpFormatter',

'MetavarTypeHelpFormatter',

'Namespace',

'Action',

'ONE_OR_MORE',

'OPTIONAL',

'PARSER',

'REMAINDER',

'SUPPRESS',

'ZERO_OR_MORE',

]

import collections as _collections

import copy as _copy

import os as _os

import re as _re

import sys as _sys

import textwrap as _textwrap

from gettext import gettext as _, ngettext

SUPPRESS = '==SUPPRESS=='

OPTIONAL = '?'

ZERO_OR_MORE = '*'

ONE_OR_MORE = '+'

PARSER = 'A...'

REMAINDER = '...'

_UNRECOGNIZED_ARGS_ATTR = '_unrecognized_args'

# =============================

# Utility functions and classes

# =============================

class _AttributeHolder(object):

"""Abstract base class that provides __repr__.

The __repr__ method returns a string in the format::

ClassName(attr=name, attr=name, ...)

The attributes are determined either by a class-level attribute,

'_kwarg_names', or by inspecting the instance __dict__.

"""

def __repr__(self):

type_name = type(self).__name__

arg_strings = []

for arg in self._get_args():

arg_strings.append(repr(arg))

for name, value in self._get_kwargs():

arg_strings.append('%s=%r' % (name, value))

return '%s(%s)' % (type_name, ', '.join(arg_strings))

def _get_kwargs(self):

return sorted(self.__dict__.items())

def _get_args(self):

return []

def _ensure_value(namespace, name, value):

if getattr(namespace, name, None) is None:

setattr(namespace, name, value)

return getattr(namespace, name)

# ===============

# Formatting Help

# ===============

class HelpFormatter(object):

"""Formatter for generating usage messages and argument help strings.

Only the name of this class is considered a public API. All the methods

provided by the class are considered an implementation detail.

"""

def __init__(self,

prog,

indent_increment=2,

max_help_position=24,

width=None):

# default setting for width

if width is None:

try:

width = int(_os.environ['COLUMNS'])

except (KeyError, ValueError):

width = 80

width -= 2

self._prog = prog

self._indent_increment = indent_increment

self._max_help_position = max_help_position

self._width = width

self._current_indent = 0

self._level = 0

self._action_max_length = 0

self._root_section = self._Section(self, None)

self._current_section = self._root_section

self._whitespace_matcher = _re.compile(r'\s+')

self._long_break_matcher = _re.compile(r'\n\n\n+')

# ===============================

# Section and indentation methods

# ===============================

def _indent(self):

self._current_indent += self._indent_increment

self._level += 1

def _dedent(self):

self._current_indent -= self._indent_increment

assert self._current_indent >= 0, 'Indent decreased below 0.'

self._level -= 1

class _Section(object):

def __init__(self, formatter, parent, heading=None):

self.formatter = formatter

self.parent = parent

self.heading = heading

self.items = []

def format_help(self):

# format the indented section

if self.parent is not None:

self.formatter._indent()

join = self.formatter._join_parts

for func, args in self.items:

func(*args)

item_help = join([func(*args) for func, args in self.items])

if self.parent is not None:

self.formatter._dedent()

# return nothing if the section was empty

if not item_help:

return ''

# add the heading if the section was non-empty

if self.heading is not SUPPRESS and self.heading is not None:

current_indent = self.formatter._current_indent

heading = '%*s%s:\n' % (current_indent, '', self.heading)

else:

heading = ''

# join the section-initial newline, the heading and the help

return join(['\n', heading, item_help, '\n'])

def _add_item(self, func, args):

self._current_section.items.append((func, args))

# ========================

# Message building methods

# ========================

def start_section(self, heading):

self._indent()

section = self._Section(self, self._current_section, heading)

self._add_item(section.format_help, [])

self._current_section = section

def end_section(self):

self._current_section = self._current_section.parent

self._dedent()

def add_text(self, text):

if text is not SUPPRESS and text is not None:

self._add_item(self._format_text, [text])

def add_usage(self, usage, actions, groups, prefix=None):

if usage is not SUPPRESS:

args = usage, actions, groups, prefix

self._add_item(self._format_usage, args)

def add_argument(self, action):

if action.help is not SUPPRESS:

# find all invocations

get_invocation = self._format_action_invocation

invocations = [get_invocation(action)]

for subaction in self._iter_indented_subactions(action):

invocations.append(get_invocation(subaction))

# update the maximum item length

invocation_length = max([len(s) for s in invocations])

action_length = invocation_length + self._current_indent

self._action_max_length = max(self._action_max_length,

action_length)

# add the item to the list

self._add_item(self._format_action, [action])

def add_arguments(self, actions):

for action in actions:

self.add_argument(action)

# =======================

# Help-formatting methods

# =======================

def format_help(self):

help = self._root_section.format_help()

if help:

help = self._long_break_matcher.sub('\n\n', help)

help = help.strip('\n') + '\n'

return help

def _join_parts(self, part_strings):

return ''.join([part

for part in part_strings

if part and part is not SUPPRESS])

def _format_usage(self, usage, actions, groups, prefix):

if prefix is None:

prefix = _('usage: ')

# if usage is specified, use that

if usage is not None:

usage = usage % dict(prog=self._prog)

# if no optionals or positionals are available, usage is just prog

elif usage is None and not actions:

usage = '%(prog)s' % dict(prog=self._prog)

# if optionals and positionals are available, calculate usage

elif usage is None:

prog = '%(prog)s' % dict(prog=self._prog)

# split optionals from positionals

optionals = []

positionals = []

for action in actions:

if action.option_strings:

optionals.append(action)

else:

positionals.append(action)

# build full usage string

format = self._format_actions_usage

action_usage = format(optionals + positionals, groups)

usage = ' '.join([s for s in [prog, action_usage] if s])

# wrap the usage parts if it's too long

text_width = self._width - self._current_indent

if len(prefix) + len(usage) > text_width:

# break usage into wrappable parts

part_regexp = r'\(.*?\)+|\[.*?\]+|\S+'

opt_usage = format(optionals, groups)

pos_usage = format(positionals, groups)

opt_parts = _re.findall(part_regexp, opt_usage)

pos_parts = _re.findall(part_regexp, pos_usage)

assert ' '.join(opt_parts) == opt_usage

assert ' '.join(pos_parts) == pos_usage

# helper for wrapping lines

def get_lines(parts, indent, prefix=None):

lines = []

line = []

if prefix is not None:

line_len = len(prefix) - 1

else:

line_len = len(indent) - 1

for part in parts:

if line_len + 1 + len(part) > text_width:

lines.append(indent + ' '.join(line))

line = []

line_len = len(indent) - 1

line.append(part)

line_len += len(part) + 1

if line:

lines.append(indent + ' '.join(line))

if prefix is not None:

lines[0] = lines[0][len(indent):]

return lines

# if prog is short, follow it with optionals or positionals

if len(prefix) + len(prog) <= 0.75 * text_width:

indent = ' ' * (len(prefix) + len(prog) + 1)

if opt_parts:

lines = get_lines([prog] + opt_parts, indent, prefix)

lines.extend(get_lines(pos_parts, indent))

elif pos_parts:

lines = get_lines([prog] + pos_parts, indent, prefix)

else:

lines = [prog]

# if prog is long, put it on its own line

else:

indent = ' ' * len(prefix)

parts = opt_parts + pos_parts

lines = get_lines(parts, indent)

if len(lines) > 1:

lines = []

lines.extend(get_lines(opt_parts, indent))

lines.extend(get_lines(pos_parts, indent))

lines = [prog] + lines

# join lines into usage

usage = '\n'.join(lines)

# prefix with 'usage:'

return '%s%s\n\n' % (prefix, usage)

def _format_actions_usage(self, actions, groups):

# find group indices and identify actions in groups

group_actions = set()

inserts = {}

for group in groups:

try:

start = actions.index(group._group_actions[0])

except ValueError:

continue

else:

end = start + len(group._group_actions)

if actions[start:end] == group._group_actions:

for action in group._group_actions:

group_actions.add(action)

if not group.required:

if start in inserts:

inserts[start] += ' ['

else:

inserts[start] = '['

inserts[end] = ']'

else:

if start in inserts:

inserts[start] += ' ('

else:

inserts[start] = '('

inserts[end] = ')'

for i in range(start + 1, end):

inserts[i] = '|'

# collect all actions format strings

parts = []

for i, action in enumerate(actions):

# suppressed arguments are marked with None

# remove | separators for suppressed arguments

if action.help is SUPPRESS:

parts.append(None)

if inserts.get(i) == '|':

inserts.pop(i)

elif inserts.get(i + 1) == '|':

inserts.pop(i + 1)

# produce all arg strings

elif not action.option_strings:

default = self._get_default_metavar_for_positional(action)

part = self._format_args(action, default)

# if it's in a group, strip the outer []

if action in group_actions:

if part[0] == '[' and part[-1] == ']':

part = part[1:-1]

# add the action string to the list

parts.append(part)

# produce the first way to invoke the option in brackets

else:

option_string = action.option_strings[0]

# if the Optional doesn't take a value, format is:

# -s or --long

if action.nargs == 0:

part = '%s' % option_string

# if the Optional takes a value, format is:

# -s ARGS or --long ARGS

else:

default = self._get_default_metavar_for_optional(action)

args_string = self._format_args(action, default)

part = '%s %s' % (option_string, args_string)

# make it look optional if it's not required or in a group

if not action.required and action not in group_actions:

part = '[%s]' % part

# add the action string to the list

parts.append(part)

# insert things at the necessary indices

for i in sorted(inserts, reverse=True):

parts[i:i] = [inserts[i]]

# join all the action items with spaces

text = ' '.join([item for item in parts if item is not None])

# clean up separators for mutually exclusive groups

open = r'[\[(]'

close = r'[\])]'

text = _re.sub(r'(%s) ' % open, r'\1', text)

text = _re.sub(r' (%s)' % close, r'\1', text)

text = _re.sub(r'%s *%s' % (open, close), r'', text)

text = _re.sub(r'\(([^|]*)\)', r'\1', text)

text = text.strip()

# return the text

return text

def _format_text(self, text):

if '%(prog)' in text:

text = text % dict(prog=self._prog)

text_width = self._width - self._current_indent

indent = ' ' * self._current_indent

return self._fill_text(text, text_width, indent) + '\n\n'

def _format_action(self, action):

# determine the required width and the entry label

help_position = min(self._action_max_length + 2,

self._max_help_position)

help_width = self._width - help_position

action_width = help_position - self._current_indent - 2

action_header = self._format_action_invocation(action)

# ho nelp; start on same line and add a final newline

if not action.help:

tup = self._current_indent, '', action_header

action_header = '%*s%s\n' % tup

# short action name; start on the same line and pad two spaces

elif len(action_header) <= action_width:

tup = self._current_indent, '', action_width, action_header

action_header = '%*s%-*s ' % tup

indent_first = 0

# long action name; start on the next line

else:

tup = self._current_indent, '', action_header

action_header = '%*s%s\n' % tup

indent_first = help_position

# collect the pieces of the action help

parts = [action_header]

# if there was help for the action, add lines of help text

if action.help:

help_text = self._expand_help(action)

help_lines = self._split_lines(help_text, help_width)

parts.append('%*s%s\n' % (indent_first, '', help_lines[0]))

for line in help_lines[1:]:

parts.append('%*s%s\n' % (help_position, '', line))

# or add a newline if the description doesn't end with one

elif not action_header.endswith('\n'):

parts.append('\n')

# if there are any sub-actions, add their help as well

for subaction in self._iter_indented_subactions(action):

parts.append(self._format_action(subaction))

# return a single string

return self._join_parts(parts)

def _format_action_invocation(self, action):

if not action.option_strings:

default = self._get_default_metavar_for_positional(action)

metavar, = self._metavar_formatter(action, default)(1)

return metavar

else:

parts = []

# if the Optional doesn't take a value, format is:

# -s, --long

if action.nargs == 0:

parts.extend(action.option_strings)

# if the Optional takes a value, format is:

# -s ARGS, --long ARGS

else:

default = self._get_default_metavar_for_optional(action)

args_string = self._format_args(action, default)

for option_string in action.option_strings:

parts.append('%s %s' % (option_string, args_string))

return ', '.join(parts)

def _metavar_formatter(self, action, default_metavar):

if action.metavar is not None:

result = action.metavar

elif action.choices is not None:

choice_strs = [str(choice) for choice in action.choices]

result = '{%s}' % ','.join(choice_strs)

else:

result = default_metavar

def format(tuple_size):

if isinstance(result, tuple):

return result

else:

return (result, ) * tuple_size

return format

def _format_args(self, action, default_metavar):

get_metavar = self._metavar_formatter(action, default_metavar)

if action.nargs is None:

result = '%s' % get_metavar(1)

elif action.nargs == OPTIONAL:

result = '[%s]' % get_metavar(1)

elif action.nargs == ZERO_OR_MORE:

result = '[%s [%s ...]]' % get_metavar(2)

elif action.nargs == ONE_OR_MORE:

result = '%s [%s ...]' % get_metavar(2)

elif action.nargs == REMAINDER:

result = '...'

elif action.nargs == PARSER:

result = '%s ...' % get_metavar(1)

else:

formats = ['%s' for _ in range(action.nargs)]

result = ' '.join(formats) % get_metavar(action.nargs)

return result

def _expand_help(self, action):

params = dict(vars(action), prog=self._prog)

for name in list(params):

if params[name] is SUPPRESS:

del params[name]

for name in list(params):

if hasattr(params[name], '__name__'):

params[name] = params[name].__name__

if params.get('choices') is not None:

choices_str = ', '.join([str(c) for c in params['choices']])

params['choices'] = choices_str

return self._get_help_string(action) % params

def _iter_indented_subactions(self, action):

try:

get_subactions = action._get_subactions

except AttributeError:

pass

else:

self._indent()

yield from get_subactions()

self._dedent()

def _split_lines(self, text, width):

text = self._whitespace_matcher.sub(' ', text).strip()

return _textwrap.wrap(text, width)

def _fill_text(self, text, width, indent):

text = self._whitespace_matcher.sub(' ', text).strip()

return _textwrap.fill(text, width, initial_indent=indent,

subsequent_indent=indent)

def _get_help_string(self, action):

return action.help

def _get_default_metavar_for_optional(self, action):

return action.dest.upper()

def _get_default_metavar_for_positional(self, action):

return action.dest

class RawDescriptionHelpFormatter(HelpFormatter):

"""Help message formatter which retains any formatting in descriptions.

Only the name of this class is considered a public API. All the methods

provided by the class are considered an implementation detail.

"""

def _fill_text(self, text, width, indent):

return ''.join(indent + line for line in text.splitlines(keepends=True))

class RawTextHelpFormatter(RawDescriptionHelpFormatter):

"""Help message formatter which retains formatting of all help text.

Only the name of this class is considered a public API. All the methods

provided by the class are considered an implementation detail.

"""

def _split_lines(self, text, width):

return text.splitlines()

class ArgumentDefaultsHelpFormatter(HelpFormatter):

"""Help message formatter which adds default values to argument help.

Only the name of this class is considered a public API. All the methods

provided by the class are considered an implementation detail.

"""

def _get_help_string(self, action):

help = action.help

if '%(default)' not in action.help:

if action.default is not SUPPRESS:

defaulting_nargs = [OPTIONAL, ZERO_OR_MORE]

if action.option_strings or action.nargs in defaulting_nargs:

help += ' (default: %(default)s)'

return help

class MetavarTypeHelpFormatter(HelpFormatter):

"""Help message formatter which uses the argument 'type' as the default

metavar value (instead of the argument 'dest')

Only the name of this class is considered a public API. All the methods

provided by the class are considered an implementation detail.

"""

def _get_default_metavar_for_optional(self, action):

return action.type.__name__

def _get_default_metavar_for_positional(self, action):

return action.type.__name__

# =====================

# Options and Arguments

# =====================

def _get_action_name(argument):

if argument is None:

return None

elif argument.option_strings:

return '/'.join(argument.option_strings)

elif argument.metavar not in (None, SUPPRESS):

return argument.metavar

elif argument.dest not in (None, SUPPRESS):

return argument.dest

else:

return None

class ArgumentError(Exception):

"""An error from creating or using an argument (optional or positional).

The string value of this exception is the message, augmented with

information about the argument that caused it.

"""

def __init__(self, argument, message):

self.argument_name = _get_action_name(argument)

self.message = message

def __str__(self):

if self.argument_name is None:

format = '%(message)s'

else:

format = 'argument %(argument_name)s: %(message)s'

return format % dict(message=self.message,

argument_name=self.argument_name)

class ArgumentTypeError(Exception):

"""An error from trying to convert a command line string to a type."""

pass

# ==============

# Action classes

# ==============

class Action(_AttributeHolder):

"""Information about how to convert command line strings to Python objects.

Action objects are used by an ArgumentParser to represent the information

needed to parse a single argument from one or more strings from the

command line. The keyword arguments to the Action constructor are also

all attributes of Action instances.

Keyword Arguments:

- option_strings -- A list of command-line option strings which

should be associated with this action.

- dest -- The name of the attribute to hold the created object(s)

- nargs -- The number of command-line arguments that should be

consumed. By default, one argument will be consumed and a single

value will be produced. Other values include:

- N (an integer) consumes N arguments (and produces a list)

- '?' consumes zero or one arguments

- '*' consumes zero or more arguments (and produces a list)

- '+' consumes one or more arguments (and produces a list)

Note that the difference between the default and nargs=1 is that

with the default, a single value will be produced, while with

nargs=1, a list containing a single value will be produced.

- const -- The value to be produced if the option is specified and the

option uses an action that takes no values.

- default -- The value to be produced if the option is not specified.

- type -- A callable that accepts a single string argument, and

returns the converted value. The standard Python types str, int,

float, and complex are useful examples of such callables. If None,

str is used.

- choices -- A container of values that should be allowed. If not None,

after a command-line argument has been converted to the appropriate

type, an exception will be raised if it is not a member of this

collection.

- required -- True if the action must always be specified at the

command line. This is only meaningful for optional command-line

arguments.

- help -- The help string describing the argument.

- metavar -- The name to be used for the option's argument with the

help string. If None, the 'dest' value will be used as the name.

"""

def __init__(self,

option_strings,

dest,

nargs=None,

const=None,

default=None,

type=None,

choices=None,

required=False,

help=None,

metavar=None):

self.option_strings = option_strings

self.dest = dest

self.nargs = nargs

self.const = const

self.default = default

self.type = type

self.choices = choices

self.required = required

self.help = help

self.metavar = metavar

def _get_kwargs(self):

names = [

'option_strings',

'dest',

'nargs',

'const',

'default',

'type',

'choices',

'help',

'metavar',

]

return [(name, getattr(self, name)) for name in names]

def __call__(self, parser, namespace, values, option_string=None):

raise NotImplementedError(_('.__call__() not defined'))

class _StoreAction(Action):

def __init__(self,

option_strings,

dest,

nargs=None,

const=None,

default=None,

type=None,

choices=None,

required=False,

help=None,

metavar=None):

if nargs == 0:

raise ValueError('nargs for store actions must be > 0; if you '

'have nothing to store, actions such as store '

'true or store const may be more appropriate')

if const is not None and nargs != OPTIONAL:

raise ValueError('nargs must be %r to supply const' % OPTIONAL)

super(_StoreAction, self).__init__(

option_strings=option_strings,

dest=dest,

nargs=nargs,

const=const,

default=default,

type=type,

choices=choices,

required=required,

help=help,

metavar=metavar)

def __call__(self, parser, namespace, values, option_string=None):

setattr(namespace, self.dest, values)

class _StoreConstAction(Action):

def __init__(self,

option_strings,

dest,

const,

default=None,

required=False,

help=None,

metavar=None):

super(_StoreConstAction, self).__init__(

option_strings=option_strings,

dest=dest,

nargs=0,

const=const,

default=default,

required=required,

help=help)

def __call__(self, parser, namespace, values, option_string=None):

setattr(namespace, self.dest, self.const)

class _StoreTrueAction(_StoreConstAction):

def __init__(self,

option_strings,

dest,

default=False,

required=False,

help=None):

super(_StoreTrueAction, self).__init__(

option_strings=option_strings,

dest=dest,

const=True,

default=default,

required=required,

help=help)

class _StoreFalseAction(_StoreConstAction):

def __init__(self,

option_strings,

dest,

default=True,

required=False,

help=None):

super(_StoreFalseAction, self).__init__(

option_strings=option_strings,

dest=dest,

const=False,

default=default,

required=required,

help=help)

class _AppendAction(Action):

def __init__(self,

option_strings,

dest,

nargs=None,

const=None,

default=None,

type=None,

choices=None,

required=False,

help=None,

metavar=None):

if nargs == 0:

raise ValueError('nargs for append actions must be > 0; if arg '

'strings are not supplying the value to append, '

'the append const action may be more appropriate')

if const is not None and nargs != OPTIONAL:

raise ValueError('nargs must be %r to supply const' % OPTIONAL)

super(_AppendAction, self).__init__(

option_strings=option_strings,

dest=dest,

nargs=nargs,

const=const,

default=default,

type=type,

choices=choices,

required=required,

help=help,

metavar=metavar)

def __call__(self, parser, namespace, values, option_string=None):

items = _copy.copy(_ensure_value(namespace, self.dest, []))

items.append(values)

setattr(namespace, self.dest, items)

class _AppendConstAction(Action):

def __init__(self,

option_strings,

dest,

const,

default=None,

required=False,

help=None,

metavar=None):

super(_AppendConstAction, self).__init__(

option_strings=option_strings,

dest=dest,

nargs=0,

const=const,

default=default,

required=required,

help=help,

metavar=metavar)

def __call__(self, parser, namespace, values, option_string=None):

items = _copy.copy(_ensure_value(namespace, self.dest, []))

items.append(self.const)

setattr(namespace, self.dest, items)

class _CountAction(Action):

def __init__(self,

option_strings,

dest,

default=None,

required=False,

help=None):

super(_CountAction, self).__init__(

option_strings=option_strings,

dest=dest,

nargs=0,

default=default,

required=required,

help=help)

def __call__(self, parser, namespace, values, option_string=None):

new_count = _ensure_value(namespace, self.dest, 0) + 1

setattr(namespace, self.dest, new_count)

class _HelpAction(Action):

View remainder of file in raw view

cpython/Lib/argparse.py at 8e7586bd44cf2a117228bb8d2b2de52ae1e88fab · python/cpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

argparse.py

Latest commit

History

Breadcrumbs

argparse.py

File metadata and controls