运行时错误：调用Python对象时超出最大递归深度

Question

这个错误是在我尝试运行一个测试用例时出现的，这个测试用例写在我名为“administration”的django应用的models.py文件里：

from django.test import Client, TestCase
from django.core import mail


class ClientTest( TestCase ):

    fixtures = [ 'testdata.json' ]

    def test_get_register( self ):
        response = self.client.get( '/accounts/register/', {} )
        self.assertEqual( response.status_code, 200 )

错误具体出现在这一行：

response = self.client.get( '/accounts/register/', {} ) 

我的django版本是1.2.1，python版本是2.6，satchmo版本是0.9.2-pre hg-unknown。我是在windows平台（xp sp2）上编写代码的。

运行测试用例的命令是：

python manage.py test administration

完整的错误日志如下：

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 121, in by_host

    site = by_host(host=host[4:], id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 124, in by_host

    site = by_host(host = 'www.%s' % host, id_only=id_only)
  File "build\bdist.win32\egg\threaded_multihost\sites.py", line 101, in by_host

    site = Site.objects.get(domain=host)
  File "C:\django\django\db\models\manager.py", line 132, in get
    return self.get_query_set().get(*args, **kwargs)
  File "C:\django\django\db\models\query.py", line 336, in get
    num = len(clone)
  File "C:\django\django\db\models\query.py", line 81, in __len__
    self._result_cache = list(self.iterator())
  File "C:\django\django\db\models\query.py", line 269, in iterator
    for row in compiler.results_iter():
  File "C:\django\django\db\models\sql\compiler.py", line 672, in results_iter
    for rows in self.execute_sql(MULTI):
  File "C:\django\django\db\models\sql\compiler.py", line 717, in execute_sql
    sql, params = self.as_sql()
  File "C:\django\django\db\models\sql\compiler.py", line 65, in as_sql
    where, w_params = self.query.where.as_sql(qn=qn, connection=self.connection)

  File "C:\django\django\db\models\sql\where.py", line 91, in as_sql
    sql, params = child.as_sql(qn=qn, connection=connection)
  File "C:\django\django\db\models\sql\where.py", line 94, in as_sql
    sql, params = self.make_atom(child, qn, connection)
  File "C:\django\django\db\models\sql\where.py", line 141, in make_atom
    lvalue, params = lvalue.process(lookup_type, params_or_value, connection)
  File "C:\django\django\db\models\sql\where.py", line 312, in process
    connection=connection, prepared=True)
  File "C:\django\django\db\models\fields\subclassing.py", line 53, in inner
    return func(*args, **kwargs)
  File "C:\django\django\db\models\fields\subclassing.py", line 53, in inner
    return func(*args, **kwargs)
  File "C:\django\django\db\models\fields\__init__.py", line 323, in get_db_prep
_lookup
    return [self.get_db_prep_value(value, connection=connection, prepared=prepar
ed)]
  File "C:\django\django\db\models\fields\subclassing.py", line 53, in inner
    return func(*args, **kwargs)
  File "C:\django\django\db\models\fields\subclassing.py", line 53, in inner
    return func(*args, **kwargs)
RuntimeError: maximum recursion depth exceeded while calling a Python object

----------------------------------------------------------------------
Ran 7 tests in 48.453s

FAILED (errors=1)
Destroying test database 'default'...

Answer 1

Django的测试客户端使用默认的基本网址：

http://testserver/

这意味着你的测试网址 /accounts/register/ 实际上变成了：

http://testserver/accounts/register/

所以你需要在Django的sites.site模型中添加'testserver'作为基本网址。

如果不这样做，Django客户端找不到'testserver'这个域名，就会导致最大递归深度超出限制。