Question

我正在使用pdb（实际上是ipdb）来调试我的Django models.py。特别是我正在尝试调试这些代码行：

def add_can_view( sender, **kwargs ) :
    #import ipdb; ipdb.set_trace()
    for content_type in ContentType.objects.all():
        Permission.objects.create(
            content_type = content_type,
            codename     = 'view_{}'.format( content_type.model ),
            name         = 'Can view {}'.format( content_type.name )
        )

post_syncdb.connect( add_can_view )

IntegrityError中提供的上述代码在python manage.py syncdb运行时出现ERROR: An unexpected error occurred while tokenizing input The following traceback may be corrupted or invalid The error message is: ('EOF in multi-line statement', (11, 0)) --------------------------------------------------------------------------- IntegrityError Traceback (most recent call last) /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/IPython/utils/py3compat.pyc in execfile(fname, *where) 173 else: 174 filename = fname --> 175 __builtin__.execfile(filename, *where) /Users/hobbes3/Sites/mysite/manage.py in <module>() 8 from django.core.management import execute_from_command_line 9 ---> 10 execute_from_command_line(sys.argv) /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/__init__.pyc in execute_from_command_line(argv) 441 """ 442 utility = ManagementUtility(argv) --> 443 utility.execute() 444 445 def execute_manager(settings_mod, argv=None): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/__init__.pyc in execute(self) 380 sys.stdout.write(self.main_help_text() + '\n') 381 else: --> 382 self.fetch_command(subcommand).run_from_argv(self.argv) 383 384 def setup_environ(settings_mod, original_settings_path=None): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/base.pyc in run_from_argv(self, argv) 194 options, args = parser.parse_args(argv[2:]) 195 handle_default_options(options) --> 196 self.execute(*args, **options.__dict__) 197 198 def execute(self, *args, **options): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/base.pyc in execute(self, *args, **options) 230 if self.requires_model_validation: 231 self.validate() --> 232 output = self.handle(*args, **options) 233 if output: 234 if self.output_transaction: /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/base.pyc in handle(self, *args, **options) 369 if args: 370 raise CommandError("Command doesn't accept any arguments") --> 371 return self.handle_noargs(**options) 372 373 def handle_noargs(self, **options): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/South-0.7.4-py2.7.egg/south/management/commands/syncdb.pyc in handle_noargs(self, migrate_all, **options) 88 89 # OK, run the actual syncdb ---> 90 syncdb.Command().execute(**options) 91 92 settings.INSTALLED_APPS = old_installed /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/base.pyc in execute(self, *args, **options) 230 if self.requires_model_validation: 231 self.validate() --> 232 output = self.handle(*args, **options) 233 if output: 234 if self.output_transaction: /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/base.pyc in handle(self, *args, **options) 369 if args: 370 raise CommandError("Command doesn't accept any arguments") --> 371 return self.handle_noargs(**options) 372 373 def handle_noargs(self, **options): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/commands/syncdb.pyc in handle_noargs(self, **options) 108 # Send the post_syncdb signal, so individual apps can do whatever they need 109 # to do at this point. --> 110 emit_post_sync_signal(created_models, verbosity, interactive, db) 111 112 # The connection may have been closed by a syncdb handler. /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/core/management/sql.pyc in emit_post_sync_signal(created_models, verbosity, interactive, db) 187 models.signals.post_syncdb.send(sender=app, app=app, 188 created_models=created_models, verbosity=verbosity, --> 189 interactive=interactive, db=db) /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/dispatch/dispatcher.pyc in send(self, sender, **named) 170 171 for receiver in self._live_receivers(_make_id(sender)): --> 172 response = receiver(signal=self, sender=sender, **named) 173 responses.append((receiver, response)) 174 return responses /Users/hobbes3/Sites/mysite/doors/signals.py in add_can_view(sender, **kwargs) 8 content_type = content_type, 9 codename = 'view_{}'.format( content_type.model ), ---> 10 name = 'Can view {}'.format( content_type.name ) 11 ) 12 /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/manager.pyc in create(self, **kwargs) 135 136 def create(self, **kwargs): --> 137 return self.get_query_set().create(**kwargs) 138 139 def bulk_create(self, *args, **kwargs): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/query.pyc in create(self, **kwargs) 375 obj = self.model(**kwargs) 376 self._for_write = True --> 377 obj.save(force_insert=True, using=self.db) 378 return obj 379 /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/base.pyc in save(self, force_insert, force_update, using) 461 if force_insert and force_update: 462 raise ValueError("Cannot force both insert and updating in model saving.") --> 463 self.save_base(using=using, force_insert=force_insert, force_update=force_update) 464 465 save.alters_data = True /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/base.pyc in save_base(self, raw, cls, origin, force_insert, force_update, using) 549 550 update_pk = bool(meta.has_auto_field and not pk_set) --> 551 result = manager._insert([self], fields=fields, return_id=update_pk, using=using, raw=raw) 552 553 if update_pk: /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/manager.pyc in _insert(self, objs, fields, **kwargs) 201 202 def _insert(self, objs, fields, **kwargs): --> 203 return insert_query(self.model, objs, fields, **kwargs) 204 205 def _update(self, values, **kwargs): /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/query.pyc in insert_query(model, objs, fields, return_id, raw, using) 1574 query = sql.InsertQuery(model) 1575 query.insert_values(fields, objs, raw=raw) -> 1576 return query.get_compiler(using=using).execute_sql(return_id) 1577 1578 /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/models/sql/compiler.pyc in execute_sql(self, return_id) 908 cursor = self.connection.cursor() 909 for sql, params in self.as_sql(): --> 910 cursor.execute(sql, params) 911 if not (return_id and cursor): 912 return /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/backends/util.pyc in execute(self, sql, params) 38 start = time() 39 try: ---> 40 return self.cursor.execute(sql, params) 41 finally: 42 stop = time() /Users/hobbes3/.virtualenvs/doors/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.pyc in execute(self, query, args) 50 def execute(self, query, args=None): 51 try: ---> 52 return self.cursor.execute(query, args) 53 except Database.IntegrityError, e: 54 raise utils.IntegrityError, utils.IntegrityError(*tuple(e)), sys.exc_info()[2] IntegrityError: duplicate key value violates unique constraint "auth_permission_content_type_id_codename_key" DETAIL: Key (content_type_id, codename)=(2, view_group) already exists.错误：

content_type

我感觉有一个重复的content_type_id 2，当我尝试将权限两次应用到auth.group import ipdb时，会发生错误。因此，当我取消注释content_type行后，我想查看一些对象，例如<ContentType: content type>，但如果我输入该对象，那么我得到的只是{{1}}。

我知道我可以简单地查看this question来查看模型，但是如何在不知道类是什么的情况下获得字段和方法列表？

也是解决此错误的奖励点lol。

Answer 1

使用dir（例如dir(content_type)）获取属性列表（包括方法）。

关于django模型，_meta属性中还有很多信息。使用dir(my_model_object._meta)探索它。

Answer 2

您的选择是：

dir获取对象的属性和方法列表
content_type.__class__了解对象的类
help在控制台中显示文档，以便您无需查找

Answer 3

由于您使用ipdb（而不是pdb），dir的更快替代方法是使用内置标签页：

ipdb> foo=""
ipdb> foo.           #press tab after writing the dot
foo.capitalize  foo.islower     foo.rpartition
foo.center      foo.isspace     foo.rsplit
foo.count       foo.istitle     foo.rstrip
foo.decode      foo.isupper     foo.split
foo.encode      foo.join        foo.splitlines
foo.endswith    foo.ljust       foo.startswith
foo.expandtabs  foo.lower       foo.strip
foo.find        foo.lstrip      foo.swapcase
foo.format      foo.partition   foo.title
foo.index       foo.replace     foo.translate
foo.isalnum     foo.rfind       foo.upper
foo.isalpha     foo.rindex      foo.zfill
foo.isdigit     foo.rjusthere

如果您不了解它，您还可以使用制表符完成变量名称

如何使用Python的pdb获取有关对象（字段和方法列表）的更详细信息？

3 个答案: