]> git.scottworley.com Git - pinch/blob - pinch.py
New pylint likes 'with'
[pinch] / pinch.py
1 import argparse
2 import configparser
3 import filecmp
4 import functools
5 import getpass
6 import hashlib
7 import operator
8 import os
9 import os.path
10 import shlex
11 import shutil
12 import subprocess
13 import sys
14 import tarfile
15 import tempfile
16 import types
17 import urllib.parse
18 import urllib.request
19 import xml.dom.minidom
20
21 from typing import (
22 Callable,
23 Dict,
24 Iterable,
25 List,
26 Mapping,
27 NamedTuple,
28 NewType,
29 Optional,
30 Set,
31 Tuple,
32 Type,
33 TypeVar,
34 Union,
35 )
36
37 import git_cache
38
39 # Use xdg module when it's less painful to have as a dependency
40
41
42 class XDG(NamedTuple):
43 XDG_CACHE_HOME: str
44
45
46 xdg = XDG(
47 XDG_CACHE_HOME=os.getenv(
48 'XDG_CACHE_HOME',
49 os.path.expanduser('~/.cache')))
50
51
52 class VerificationError(Exception):
53 pass
54
55
56 class Verification:
57
58 def __init__(self) -> None:
59 self.line_length = 0
60
61 def status(self, s: str) -> None:
62 print(s, end=' ', file=sys.stderr, flush=True)
63 self.line_length += 1 + len(s) # Unicode??
64
65 @staticmethod
66 def _color(s: str, c: int) -> str:
67 return '\033[%2dm%s\033[00m' % (c, s)
68
69 def result(self, r: bool) -> None:
70 message, color = {True: ('OK ', 92), False: ('FAIL', 91)}[r]
71 length = len(message)
72 cols = shutil.get_terminal_size().columns or 80
73 pad = (cols - (self.line_length + length)) % cols
74 print(' ' * pad + self._color(message, color), file=sys.stderr)
75 self.line_length = 0
76 if not r:
77 raise VerificationError()
78
79 def check(self, s: str, r: bool) -> None:
80 self.status(s)
81 self.result(r)
82
83 def ok(self) -> None:
84 self.result(True)
85
86
87 Digest16 = NewType('Digest16', str)
88 Digest32 = NewType('Digest32', str)
89
90
91 class ChannelTableEntry(types.SimpleNamespace):
92 absolute_url: str
93 digest: Digest16
94 file: str
95 size: int
96 url: str
97
98
99 class AliasPin(NamedTuple):
100 pass
101
102
103 class SymlinkPin(NamedTuple):
104 @property
105 def release_name(self) -> str:
106 return 'link'
107
108
109 class GitPin(NamedTuple):
110 git_revision: str
111 release_name: str
112
113
114 class ChannelPin(NamedTuple):
115 git_revision: str
116 release_name: str
117 tarball_url: str
118 tarball_sha256: str
119
120
121 Pin = Union[AliasPin, SymlinkPin, GitPin, ChannelPin]
122
123
124 def copy_to_nix_store(v: Verification, filename: str) -> str:
125 v.status('Putting tarball in Nix store')
126 process = subprocess.run(
127 ['nix-store', '--add', filename], stdout=subprocess.PIPE)
128 v.result(process.returncode == 0)
129 return process.stdout.decode().strip() # type: ignore # (for old mypy)
130
131
132 def symlink_archive(v: Verification, path: str) -> str:
133 with tempfile.TemporaryDirectory() as td:
134 archive_filename = os.path.join(td, 'link.tar.gz')
135 os.symlink(path, os.path.join(td, 'link'))
136 with tarfile.open(archive_filename, mode='x:gz') as t:
137 t.add(os.path.join(td, 'link'), arcname='link')
138 return copy_to_nix_store(v, archive_filename)
139
140
141 class AliasSearchPath(NamedTuple):
142 alias_of: str
143
144 # pylint: disable=no-self-use
145 def pin(self, _: Verification, __: Optional[Pin]) -> AliasPin:
146 return AliasPin()
147
148
149 class SymlinkSearchPath(NamedTuple):
150 path: str
151
152 # pylint: disable=no-self-use
153 def pin(self, _: Verification, __: Optional[Pin]) -> SymlinkPin:
154 return SymlinkPin()
155
156 def fetch(self, v: Verification, _: Pin) -> str:
157 return symlink_archive(v, self.path)
158
159
160 class GitSearchPath(NamedTuple):
161 git_ref: str
162 git_repo: str
163
164 def pin(self, v: Verification, old_pin: Optional[Pin]) -> GitPin:
165 _, new_revision = git_cache.fetch(self.git_repo, self.git_ref)
166 if old_pin is not None:
167 assert isinstance(old_pin, GitPin)
168 verify_git_ancestry(v, self, old_pin.git_revision, new_revision)
169 return GitPin(release_name=git_revision_name(v, self, new_revision),
170 git_revision=new_revision)
171
172 def fetch(self, v: Verification, pin: Pin) -> str:
173 assert isinstance(pin, GitPin)
174 git_cache.ensure_rev_available(
175 self.git_repo, self.git_ref, pin.git_revision)
176 return git_get_tarball(v, self, pin)
177
178
179 class ChannelSearchPath(NamedTuple):
180 channel_url: str
181 git_ref: str
182 git_repo: str
183
184 def pin(self, v: Verification, old_pin: Optional[Pin]) -> ChannelPin:
185 if old_pin is not None:
186 assert isinstance(old_pin, ChannelPin)
187
188 channel_html, forwarded_url = fetch_channel(v, self)
189 table, new_gitpin = parse_channel(v, channel_html)
190 if old_pin is not None and old_pin.git_revision == new_gitpin.git_revision:
191 return old_pin
192 fetch_resources(v, new_gitpin, forwarded_url, table)
193 git_cache.ensure_rev_available(
194 self.git_repo, self.git_ref, new_gitpin.git_revision)
195 if old_pin is not None:
196 verify_git_ancestry(
197 v, self, old_pin.git_revision, new_gitpin.git_revision)
198 check_channel_contents(v, self, table, new_gitpin)
199 return ChannelPin(
200 release_name=new_gitpin.release_name,
201 tarball_url=table['nixexprs.tar.xz'].absolute_url,
202 tarball_sha256=table['nixexprs.tar.xz'].digest,
203 git_revision=new_gitpin.git_revision)
204
205 # pylint: disable=no-self-use
206 def fetch(self, v: Verification, pin: Pin) -> str:
207 assert isinstance(pin, ChannelPin)
208
209 return fetch_with_nix_prefetch_url(
210 v, pin.tarball_url, Digest16(pin.tarball_sha256))
211
212
213 SearchPath = Union[AliasSearchPath,
214 SymlinkSearchPath,
215 GitSearchPath,
216 ChannelSearchPath]
217 TarrableSearchPath = Union[GitSearchPath, ChannelSearchPath]
218
219
220 def compare(a: str, b: str) -> Tuple[List[str], List[str], List[str]]:
221
222 def throw(error: OSError) -> None:
223 raise error
224
225 def join(x: str, y: str) -> str:
226 return y if x == '.' else os.path.join(x, y)
227
228 def recursive_files(d: str) -> Iterable[str]:
229 all_files: List[str] = []
230 for path, dirs, files in os.walk(d, onerror=throw):
231 rel = os.path.relpath(path, start=d)
232 all_files.extend(join(rel, f) for f in files)
233 for dir_or_link in dirs:
234 if os.path.islink(join(path, dir_or_link)):
235 all_files.append(join(rel, dir_or_link))
236 return all_files
237
238 def exclude_dot_git(files: Iterable[str]) -> Iterable[str]:
239 return (f for f in files if not f.startswith('.git/'))
240
241 files = functools.reduce(
242 operator.or_, (set(
243 exclude_dot_git(
244 recursive_files(x))) for x in [a, b]))
245 return filecmp.cmpfiles(a, b, files, shallow=False)
246
247
248 def fetch_channel(
249 v: Verification, channel: ChannelSearchPath) -> Tuple[str, str]:
250 v.status('Fetching channel from %s' % channel.channel_url)
251 with urllib.request.urlopen(channel.channel_url, timeout=10) as request:
252 channel_html = request.read().decode()
253 forwarded_url = request.geturl()
254 v.result(request.status == 200)
255 v.check('Got forwarded', channel.channel_url != forwarded_url)
256 return channel_html, forwarded_url
257
258
259 def parse_channel(v: Verification, channel_html: str) \
260 -> Tuple[Dict[str, ChannelTableEntry], GitPin]:
261 v.status('Parsing channel description as XML')
262 d = xml.dom.minidom.parseString(channel_html)
263 v.ok()
264
265 v.status('Extracting release name:')
266 title_name = d.getElementsByTagName(
267 'title')[0].firstChild.nodeValue.split()[2]
268 h1_name = d.getElementsByTagName('h1')[0].firstChild.nodeValue.split()[2]
269 v.status(title_name)
270 v.result(title_name == h1_name)
271
272 v.status('Extracting git commit:')
273 git_commit_node = d.getElementsByTagName('tt')[0]
274 git_revision = git_commit_node.firstChild.nodeValue
275 v.status(git_revision)
276 v.ok()
277 v.status('Verifying git commit label')
278 v.result(git_commit_node.previousSibling.nodeValue == 'Git commit ')
279
280 v.status('Parsing table')
281 table: Dict[str, ChannelTableEntry] = {}
282 for row in d.getElementsByTagName('tr')[1:]:
283 name = row.childNodes[0].firstChild.firstChild.nodeValue
284 url = row.childNodes[0].firstChild.getAttribute('href')
285 size = int(row.childNodes[1].firstChild.nodeValue)
286 digest = Digest16(row.childNodes[2].firstChild.firstChild.nodeValue)
287 table[name] = ChannelTableEntry(url=url, digest=digest, size=size)
288 v.ok()
289 return table, GitPin(release_name=title_name, git_revision=git_revision)
290
291
292 def digest_string(s: bytes) -> Digest16:
293 return Digest16(hashlib.sha256(s).hexdigest())
294
295
296 def digest_file(filename: str) -> Digest16:
297 hasher = hashlib.sha256()
298 with open(filename, 'rb') as f:
299 # pylint: disable=cell-var-from-loop
300 for block in iter(lambda: f.read(4096), b''):
301 hasher.update(block)
302 return Digest16(hasher.hexdigest())
303
304
305 @functools.lru_cache
306 def _experimental_flag_needed(v: Verification) -> bool:
307 v.status('Checking Nix version')
308 process = subprocess.run(['nix', '--help'], stdout=subprocess.PIPE)
309 v.result(process.returncode == 0)
310 return b'--experimental-features' in process.stdout
311
312
313 def _nix_command(v: Verification) -> List[str]:
314 return ['nix', '--experimental-features',
315 'nix-command'] if _experimental_flag_needed(v) else ['nix']
316
317
318 def to_Digest16(v: Verification, digest32: Digest32) -> Digest16:
319 v.status('Converting digest to base16')
320 process = subprocess.run(_nix_command(v) + [
321 'to-base16',
322 '--type',
323 'sha256',
324 digest32],
325 stdout=subprocess.PIPE)
326 v.result(process.returncode == 0)
327 return Digest16(process.stdout.decode().strip())
328
329
330 def to_Digest32(v: Verification, digest16: Digest16) -> Digest32:
331 v.status('Converting digest to base32')
332 process = subprocess.run(_nix_command(v) + [
333 'to-base32',
334 '--type',
335 'sha256',
336 digest16],
337 stdout=subprocess.PIPE)
338 v.result(process.returncode == 0)
339 return Digest32(process.stdout.decode().strip())
340
341
342 def fetch_with_nix_prefetch_url(
343 v: Verification,
344 url: str,
345 digest: Digest16) -> str:
346 v.status('Fetching %s' % url)
347 process = subprocess.run(
348 ['nix-prefetch-url', '--print-path', url, digest], stdout=subprocess.PIPE)
349 v.result(process.returncode == 0)
350 prefetch_digest, path, empty = process.stdout.decode().split('\n')
351 assert empty == ''
352 v.check("Verifying nix-prefetch-url's digest",
353 to_Digest16(v, Digest32(prefetch_digest)) == digest)
354 v.status("Verifying digest of %s" % path)
355 file_digest = digest_file(path)
356 v.result(file_digest == digest)
357 return path # type: ignore # (for old mypy)
358
359
360 def fetch_resources(
361 v: Verification,
362 pin: GitPin,
363 forwarded_url: str,
364 table: Dict[str, ChannelTableEntry]) -> None:
365 for resource in ['git-revision', 'nixexprs.tar.xz']:
366 fields = table[resource]
367 fields.absolute_url = urllib.parse.urljoin(forwarded_url, fields.url)
368 fields.file = fetch_with_nix_prefetch_url(
369 v, fields.absolute_url, fields.digest)
370 v.status('Verifying git commit on main page matches git commit in table')
371 with open(table['git-revision'].file, encoding='utf-8') as rev_file:
372 v.result(rev_file.read(999) == pin.git_revision)
373
374
375 def tarball_cache_file(channel: TarrableSearchPath, pin: GitPin) -> str:
376 return os.path.join(
377 xdg.XDG_CACHE_HOME,
378 'pinch/git-tarball',
379 '%s-%s-%s' %
380 (digest_string(channel.git_repo.encode()),
381 pin.git_revision,
382 pin.release_name))
383
384
385 def verify_git_ancestry(
386 v: Verification,
387 channel: TarrableSearchPath,
388 old_revision: str,
389 new_revision: str) -> None:
390 cachedir = git_cache.git_cachedir(channel.git_repo)
391 v.status('Verifying rev is an ancestor of previous rev %s' % old_revision)
392 process = subprocess.run(['git',
393 '-C',
394 cachedir,
395 'merge-base',
396 '--is-ancestor',
397 old_revision,
398 new_revision])
399 v.result(process.returncode == 0)
400
401
402 def compare_tarball_and_git(
403 v: Verification,
404 pin: GitPin,
405 channel_contents: str,
406 git_contents: str) -> None:
407 v.status('Comparing channel tarball with git checkout')
408 match, mismatch, errors = compare(os.path.join(
409 channel_contents, pin.release_name), git_contents)
410 v.ok()
411 v.check('%d files match' % len(match), len(match) > 0)
412 v.check('%d files differ' % len(mismatch), len(mismatch) == 0)
413 expected_errors = [
414 '.git-revision',
415 '.version-suffix',
416 'nixpkgs',
417 'programs.sqlite',
418 'svn-revision']
419 benign_errors = []
420 for ee in expected_errors:
421 if ee in errors:
422 errors.remove(ee)
423 benign_errors.append(ee)
424 v.check(
425 '%d unexpected incomparable files' %
426 len(errors),
427 len(errors) == 0)
428 v.check(
429 '(%d of %d expected incomparable files)' %
430 (len(benign_errors),
431 len(expected_errors)),
432 len(benign_errors) == len(expected_errors))
433
434
435 def extract_tarball(
436 v: Verification,
437 table: Dict[str, ChannelTableEntry],
438 dest: str) -> None:
439 v.status('Extracting tarball %s' % table['nixexprs.tar.xz'].file)
440 shutil.unpack_archive(table['nixexprs.tar.xz'].file, dest)
441 v.ok()
442
443
444 def git_checkout(
445 v: Verification,
446 channel: TarrableSearchPath,
447 pin: GitPin,
448 dest: str) -> None:
449 v.status('Checking out corresponding git revision')
450 with subprocess.Popen(
451 ['git', '-C', git_cache.git_cachedir(channel.git_repo), 'archive', pin.git_revision],
452 stdout=subprocess.PIPE) as git:
453 with subprocess.Popen(['tar', 'x', '-C', dest, '-f', '-'], stdin=git.stdout) as tar:
454 if git.stdout:
455 git.stdout.close()
456 tar.wait()
457 git.wait()
458 v.result(git.returncode == 0 and tar.returncode == 0)
459
460
461 def git_get_tarball(
462 v: Verification,
463 channel: TarrableSearchPath,
464 pin: GitPin) -> str:
465 cache_file = tarball_cache_file(channel, pin)
466 if os.path.exists(cache_file):
467 with open(cache_file, encoding='utf-8') as f:
468 cached_tarball = f.read(9999)
469 if os.path.exists(cached_tarball):
470 return cached_tarball
471
472 with tempfile.TemporaryDirectory() as output_dir:
473 output_filename = os.path.join(
474 output_dir, pin.release_name + '.tar.xz')
475 with open(output_filename, 'w', encoding='utf-8') as output_file:
476 v.status(
477 'Generating tarball for git revision %s' %
478 pin.git_revision)
479 with subprocess.Popen(
480 ['git', '-C', git_cache.git_cachedir(channel.git_repo),
481 'archive', '--prefix=%s/' % pin.release_name, pin.git_revision],
482 stdout=subprocess.PIPE) as git:
483 with subprocess.Popen(['xz'], stdin=git.stdout, stdout=output_file) as xz:
484 xz.wait()
485 git.wait()
486 v.result(git.returncode == 0 and xz.returncode == 0)
487
488 store_tarball = copy_to_nix_store(v, output_filename)
489
490 os.makedirs(os.path.dirname(cache_file), exist_ok=True)
491 with open(cache_file, 'w', encoding='utf-8') as f:
492 f.write(store_tarball)
493 return store_tarball # type: ignore # (for old mypy)
494
495
496 def check_channel_metadata(
497 v: Verification,
498 pin: GitPin,
499 channel_contents: str) -> None:
500 v.status('Verifying git commit in channel tarball')
501 with open(os.path.join(channel_contents, pin.release_name, '.git-revision'),
502 encoding='utf-8') as f:
503 v.result(f.read(999) == pin.git_revision)
504
505 v.status(
506 'Verifying version-suffix is a suffix of release name %s:' %
507 pin.release_name)
508 with open(os.path.join(channel_contents, pin.release_name, '.version-suffix'),
509 encoding='utf-8') as f:
510 version_suffix = f.read(999)
511 v.status(version_suffix)
512 v.result(pin.release_name.endswith(version_suffix))
513
514
515 def check_channel_contents(
516 v: Verification,
517 channel: TarrableSearchPath,
518 table: Dict[str, ChannelTableEntry],
519 pin: GitPin) -> None:
520 with tempfile.TemporaryDirectory() as channel_contents, \
521 tempfile.TemporaryDirectory() as git_contents:
522
523 extract_tarball(v, table, channel_contents)
524 check_channel_metadata(v, pin, channel_contents)
525
526 git_checkout(v, channel, pin, git_contents)
527
528 compare_tarball_and_git(v, pin, channel_contents, git_contents)
529
530 v.status('Removing temporary directories')
531 v.ok()
532
533
534 def git_revision_name(
535 v: Verification,
536 channel: TarrableSearchPath,
537 git_revision: str) -> str:
538 v.status('Getting commit date')
539 process = subprocess.run(['git',
540 '-C',
541 git_cache.git_cachedir(channel.git_repo),
542 'log',
543 '-n1',
544 '--format=%ct-%h',
545 '--abbrev=11',
546 '--no-show-signature',
547 git_revision],
548 stdout=subprocess.PIPE)
549 v.result(process.returncode == 0 and process.stdout != b'')
550 return '%s-%s' % (os.path.basename(channel.git_repo),
551 process.stdout.decode().strip())
552
553
554 K = TypeVar('K')
555 V = TypeVar('V')
556
557
558 def partition_dict(pred: Callable[[K, V], bool],
559 d: Dict[K, V]) -> Tuple[Dict[K, V], Dict[K, V]]:
560 selected: Dict[K, V] = {}
561 remaining: Dict[K, V] = {}
562 for k, v in d.items():
563 if pred(k, v):
564 selected[k] = v
565 else:
566 remaining[k] = v
567 return selected, remaining
568
569
570 def filter_dict(d: Dict[K, V], fields: Set[K]
571 ) -> Tuple[Dict[K, V], Dict[K, V]]:
572 return partition_dict(lambda k, v: k in fields, d)
573
574
575 def read_config_section(
576 conf: configparser.SectionProxy) -> Tuple[SearchPath, Optional[Pin]]:
577 mapping: Mapping[str, Tuple[Type[SearchPath], Type[Pin]]] = {
578 'alias': (AliasSearchPath, AliasPin),
579 'channel': (ChannelSearchPath, ChannelPin),
580 'git': (GitSearchPath, GitPin),
581 'symlink': (SymlinkSearchPath, SymlinkPin),
582 }
583 SP, P = mapping[conf['type']]
584 _, all_fields = filter_dict(dict(conf.items()), set(['type']))
585 pin_fields, remaining_fields = filter_dict(all_fields, set(P._fields))
586 # Error suppression works around https://github.com/python/mypy/issues/9007
587 pin_present = pin_fields != {} or P._fields == ()
588 pin = P(**pin_fields) if pin_present else None # type: ignore
589 return SP(**remaining_fields), pin
590
591
592 def read_pinned_config_section(
593 section: str, conf: configparser.SectionProxy) -> Tuple[SearchPath, Pin]:
594 sp, pin = read_config_section(conf)
595 if pin is None:
596 raise Exception(
597 'Cannot update unpinned channel "%s" (Run "pin" before "update")' %
598 section)
599 return sp, pin
600
601
602 def read_config(filename: str) -> configparser.ConfigParser:
603 config = configparser.ConfigParser()
604 with open(filename, encoding='utf-8') as f:
605 config.read_file(f, filename)
606 return config
607
608
609 def read_config_files(
610 filenames: Iterable[str]) -> Dict[str, configparser.SectionProxy]:
611 merged_config: Dict[str, configparser.SectionProxy] = {}
612 for file in filenames:
613 config = read_config(file)
614 for section in config.sections():
615 if section in merged_config:
616 raise Exception('Duplicate channel "%s"' % section)
617 merged_config[section] = config[section]
618 return merged_config
619
620
621 def pinCommand(args: argparse.Namespace) -> None:
622 v = Verification()
623 config = read_config(args.channels_file)
624 for section in config.sections():
625 if args.channels and section not in args.channels:
626 continue
627
628 sp, old_pin = read_config_section(config[section])
629
630 config[section].update(sp.pin(v, old_pin)._asdict())
631
632 with open(args.channels_file, 'w', encoding='utf-8') as configfile:
633 config.write(configfile)
634
635
636 def updateCommand(args: argparse.Namespace) -> None:
637 v = Verification()
638 exprs: Dict[str, str] = {}
639 profile_manifest = os.path.join(args.profile, "manifest.nix")
640 search_paths: List[str] = [
641 "-I", "pinch_profile=" + args.profile,
642 "-I", "pinch_profile_manifest=" + os.readlink(profile_manifest)
643 ] if os.path.exists(profile_manifest) else []
644 config = {
645 section: read_pinned_config_section(section, conf) for section,
646 conf in read_config_files(
647 args.channels_file).items()}
648 alias, nonalias = partition_dict(
649 lambda k, v: isinstance(v[0], AliasSearchPath), config)
650
651 for section, (sp, pin) in sorted(nonalias.items()):
652 assert not isinstance(sp, AliasSearchPath) # mypy can't see through
653 assert not isinstance(pin, AliasPin) # partition_dict()
654 tarball = sp.fetch(v, pin)
655 search_paths.extend(["-I", "pinch_tarball_for_%s=%s" %
656 (pin.release_name, tarball)])
657 exprs[section] = (
658 'f: f { name = "%s"; channelName = "%%s"; src = builtins.storePath "%s"; }' %
659 (pin.release_name, tarball))
660
661 for section, (sp, pin) in alias.items():
662 assert isinstance(sp, AliasSearchPath) # For mypy
663 exprs[section] = exprs[sp.alias_of]
664
665 command = [
666 'nix-env',
667 '--profile',
668 args.profile,
669 '--show-trace',
670 '--file',
671 '<nix/unpack-channel.nix>',
672 '--install',
673 '--remove-all',
674 ] + search_paths + ['--from-expression'] + [
675 exprs[name] % name for name in sorted(exprs.keys())]
676 if args.dry_run:
677 print(' '.join(map(shlex.quote, command)))
678 else:
679 v.status('Installing channels with nix-env')
680 process = subprocess.run(command)
681 v.result(process.returncode == 0)
682
683
684 def main() -> None:
685 parser = argparse.ArgumentParser(prog='pinch')
686 subparsers = parser.add_subparsers(dest='mode', required=True)
687 parser_pin = subparsers.add_parser('pin')
688 parser_pin.add_argument('channels_file', type=str)
689 parser_pin.add_argument('channels', type=str, nargs='*')
690 parser_pin.set_defaults(func=pinCommand)
691 parser_update = subparsers.add_parser('update')
692 parser_update.add_argument('--dry-run', action='store_true')
693 parser_update.add_argument('--profile', default=(
694 '/nix/var/nix/profiles/per-user/%s/channels' % getpass.getuser()))
695 parser_update.add_argument('channels_file', type=str, nargs='+')
696 parser_update.set_defaults(func=updateCommand)
697 args = parser.parse_args()
698 args.func(args)
699
700
701 if __name__ == '__main__':
702 main()