django之urlresolver

>>> from django.utils.regex_helper import normalize
>>> bits=normalize(r'^static/(?P<path>.*)$')
>>> bits
[(u'static/%(path)s', [u'path'])]
>>> bits=normalize(r'^static/(?P<path>.*)/(?P<order>.*)$')
>>> bits
[(u'static/%(path)s/%(order)s', [u'path', u'order'])]

normalize函数返回列表，列表的元素是元组，元组的第一项是字符串，第二项是组名字。

django.conf.url可以导入include，patterns，url等函数

def include(arg, namespace=None, app_name=None):
    if app_name and not namespace:
        raise ValueError('Must specify a namespace if specifying app_name.')
    if app_name:
        warnings.warn(
            'The app_name argument to django.conf.urls.include() is deprecated. '
            'Set the app_name in the included URLconf instead.',
            RemovedInDjango20Warning, stacklevel=2
        )

    if isinstance(arg, tuple):
        # callable returning a namespace hint
        try:
            urlconf_module, app_name = arg
        except ValueError:
            if namespace:
                raise ImproperlyConfigured(
                    'Cannot override the namespace for a dynamic module that provides a namespace'
                )
            warnings.warn(
                'Passing a 3-tuple to django.conf.urls.include() is deprecated. '
                'Pass a 2-tuple containing the list of patterns and app_name, '
                'and provide the namespace argument to include() instead.',
                RemovedInDjango20Warning, stacklevel=2
            )
            urlconf_module, app_name, namespace = arg
    else:
        # No namespace hint - use manually provided namespace
        urlconf_module = arg

    if isinstance(urlconf_module, six.string_types):#urlconf_module可以是字符串，导入该字符串
        urlconf_module = import_module(urlconf_module)
    patterns = getattr(urlconf_module, 'urlpatterns', urlconf_module)
    app_name = getattr(urlconf_module, 'app_name', app_name)
    if namespace and not app_name:
        warnings.warn(
            'Specifying a namespace in django.conf.urls.include() without '
            'providing an app_name is deprecated. Set the app_name attribute '
            'in the included module, or pass a 2-tuple containing the list of '
            'patterns and app_name instead.',
            RemovedInDjango20Warning, stacklevel=2
        )

    namespace = namespace or app_name

    # Make sure we can iterate through the patterns (without this, some
    # testcases will break).
    if isinstance(patterns, (list, tuple)):
        for url_pattern in patterns:
            # Test if the LocaleRegexURLResolver is used within the include;
            # this should throw an error since this is not allowed!
            if isinstance(url_pattern, LocaleRegexURLResolver):
                raise ImproperlyConfigured(
                    'Using i18n_patterns in an included URLconf is not allowed.')

    return (urlconf_module, app_name, namespace)

def patterns(prefix, *args):#返回列表
    warnings.warn(
        'django.conf.urls.patterns() is deprecated and will be removed in '
        'Django 1.10. Update your urlpatterns to be a list of '
        'django.conf.urls.url() instances instead.',
        RemovedInDjango110Warning, stacklevel=2
    )
    pattern_list = []
    for t in args:
        if isinstance(t, (list, tuple)):
            t = url(prefix=prefix, *t)
        elif isinstance(t, RegexURLPattern):
            t.add_prefix(prefix)
        pattern_list.append(t)
    return pattern_list

def url(regex, view, kwargs=None, name=None, prefix=''):
    if isinstance(view, (list, tuple)):#返回RegexURLResolver对象
        # For include(...) processing.
        urlconf_module, app_name, namespace = view
        return RegexURLResolver(regex, urlconf_module, kwargs, app_name=app_name, namespace=namespace)
    else:
        if isinstance(view, six.string_types):
            warnings.warn(
                'Support for string view arguments to url() is deprecated and '
                'will be removed in Django 1.10 (got %s). Pass the callable '
                'instead.' % view,
                RemovedInDjango110Warning, stacklevel=2
            )
            if not view:
                raise ImproperlyConfigured('Empty URL pattern view name not permitted (for pattern %r)' % regex)
            if prefix:
                view = prefix + '.' + view
        return RegexURLPattern(regex, view, kwargs, name)#返回RegexURLPattern

class RegexURLResolver(LocaleRegexProvider):
    def __init__(self, regex, urlconf_name, default_kwargs=None, app_name=None, namespace=None):
        print "i am regxurlresolver"
        LocaleRegexProvider.__init__(self, regex)
        # urlconf_name is the dotted Python path to the module defining
        # urlpatterns. It may also be an object with an urlpatterns attribute
        # or urlpatterns itself.
        self.urlconf_name = urlconf_name
        self.callback = None
        self.default_kwargs = default_kwargs or {}
        self.namespace = namespace
        self.app_name = app_name
        self._reverse_dict = {}
        self._namespace_dict = {}
        self._app_dict = {}
        # set of dotted paths to all functions and classes that are used in
        # urlpatterns
        self._callback_strs = set()
        self._populated = False

    def __repr__(self):
        if isinstance(self.urlconf_name, list) and len(self.urlconf_name):
            # Don't bother to output the whole list, it can be huge
            urlconf_repr = '<%s list>' % self.urlconf_name[0].__class__.__name__
        else:
            urlconf_repr = repr(self.urlconf_name)
        return str('<%s %s (%s:%s) %s>') % (
            self.__class__.__name__, urlconf_repr, self.app_name,
            self.namespace, self.regex.pattern)

    def _populate(self):#初始化时会递归调用
        lookups = MultiValueDict()
        namespaces = {}
        apps = {}
        language_code = get_language()
        for pattern in reversed(self.url_patterns):#urls.py的urlpattern
            if hasattr(pattern, '_callback_str'):#回调字符串集可以用来判断是否可回调
                self._callback_strs.add(pattern._callback_str)
            elif hasattr(pattern, '_callback'):#回调对象转换为字符串
                callback = pattern._callback
                if isinstance(callback, functools.partial):
                    callback = callback.func

                if not hasattr(callback, '__name__'):
                    lookup_str = callback.__module__ + "." + callback.__class__.__name__
                else:
                    lookup_str = callback.__module__ + "." + callback.__name__
                self._callback_strs.add(lookup_str)
            p_pattern = pattern.regex.pattern#取得 RegexURLPattern对象的正则
            if p_pattern.startswith('^'):
                p_pattern = p_pattern[1:]
            if isinstance(pattern, RegexURLResolver):
                if pattern.namespace:
                    namespaces[pattern.namespace] = (p_pattern, pattern)
                    if pattern.app_name:
                        apps.setdefault(pattern.app_name, []).append(pattern.namespace)
                else:
                    parent_pat = pattern.regex.pattern#取得模式字符串
                    for name in pattern.reverse_dict:#会使得RegexURLResolver对象_populate()
                        for matches, pat, defaults in pattern.reverse_dict.getlist(name):
                            new_matches = normalize(parent_pat + pat)#完善该名字对应的内容
                            lookups.appendlist(
                                name,
                                (
                                    new_matches,
                                    p_pattern + pat,
                                    dict(defaults, **pattern.default_kwargs),
                                )
                            )
                    for namespace, (prefix, sub_pattern) in pattern.namespace_dict.items():
                        namespaces[namespace] = (p_pattern + prefix, sub_pattern)
                    for app_name, namespace_list in pattern.app_dict.items():
                        apps.setdefault(app_name, []).extend(namespace_list)
                    self._callback_strs.update(pattern._callback_strs)
            else:
                bits = normalize(p_pattern)
                lookups.appendlist(pattern.callback, (bits, p_pattern, pattern.default_args))
                if pattern.name is not None:
                    lookups.appendlist(pattern.name, (bits, p_pattern, pattern.default_args))

        self._reverse_dict[language_code] = lookups
        self._namespace_dict[language_code] = namespaces
        self._app_dict[language_code] = apps
        self._populated = True

第一次查找视图函数时，会调用_populate，这样会使得各个urls.py模板都解决。

mezzanine的urlresolver

In [27]: url.__dict__
Out[27]:
{'_app_dict': {u'en': {'admin': ['admin']}},
 '_callback_strs': {u'django.contrib.auth.admin.user_change_password',
  u'django.contrib.auth.views.password_reset',
  u'django.contrib.auth.views.password_reset_complete',
  u'django.contrib.auth.views.password_reset_confirm',
  u'django.contrib.auth.views.password_reset_done',
  u'django.contrib.sitemaps.views.sitemap',
  u'django.views.i18n.javascript_catalog',
  u'filebrowser_safe.decorators.decorator',
  u'filebrowser_safe.views._check_file',
  u'filebrowser_safe.views.browse',
  u'filebrowser_safe.views.delete',
  u'filebrowser_safe.views.mkdir',
  u'filebrowser_safe.views.rename',
  u'filebrowser_safe.views.upload',
  u'mezzanine.blog.views.blog_post_detail',
  u'mezzanine.blog.views.blog_post_feed',
  u'mezzanine.blog.views.blog_post_list',
  u'mezzanine.boot.lazy_admin.<lambda>',
  u'mezzanine.core.views.direct_to_template',
  u'mezzanine.core.views.displayable_links_js',
  u'mezzanine.core.views.edit',
  u'mezzanine.core.views.search',
  u'mezzanine.core.views.set_device',
  u'mezzanine.core.views.set_site',
  u'mezzanine.core.views.static_proxy',
  u'mezzanine.generic.views.admin_keywords_submit',
  u'mezzanine.generic.views.comment',
  u'mezzanine.generic.views.rating',
  u'mezzanine.pages.views.admin_page_ordering',
  u'mezzanine.pages.views.page'},
 '_namespace_dict': {u'en': {'admin': (u'admin/',
    <RegexURLResolver <RegexURLPattern list> (admin:admin) >)}},
 '_populated': True,
 '_regex': u'^/',
 '_regex_dict': {},
 '_reverse_dict': {u'en': <MultiValueDict: {u'comment': [([(u'comment/', [])], u
'comment/$', {})], u'rating': [([(u'rating/', [])], u'rating/$', {})], u'admin_k
eywords_submit': [([(u'admin_keywords_submit/', [])], u'admin_keywords_submit/$'
, {})], <function comment at 0x035C8830>: [([(u'comment/', [])], u'comment/$', {
})], u'fb_rename': [([(u'admin/media-library/rename/', [])], u'admin/media-libra
ry/rename/$', {})], u'blog_post_list_month': [([(u'blog/archive/%(year)s/%(month
)s/', [u'year', u'month'])], u'blog/archive/(?P<year>\\d{4})/(?P<month>\\d{1,2})
/$', {})], u'fb_mkdir': [([(u'admin/media-library/mkdir/', [])], u'admin/media-l
ibrary/mkdir/', {})], u'blog_post_list_author': [([(u'blog/author/%(username)s/'
, [u'username'])], u'blog/author/(?P<username>.*)/$', {})], u'set_device': [([(u
'set_device/%(device)s/', [u'device'])], u'set_device/(?P<device>.*)/$', {})], u
'blog_post_list_category': [([(u'blog/category/%(category)s/', [u'category'])],
u'blog/category/(?P<category>.*)/$', {})], <function _check_file at 0x035EA530>:
 [([(u'admin/media-library/check_file/', [])], u'admin/media-library/check_file/
$', {})], <function static_proxy at 0x035B0130>: [([(u'asset_proxy/', [])], u'as
set_proxy/$', {})], <function user_change_password at 0x035EA930>: [([(u'admin/a
uth/user/%(_0)s/password/', [u'_0'])], u'admin/auth/user/(\\d+)/password/$', {})
], u'blog_post_detail_day': [([(u'blog/%(year)s/%(month)s/%(day)s/%(slug)s/', [u
'year', u'month', u'day', u'slug'])], u'blog/(?P<year>\\d{4})/(?P<month>\\d{1,2}
)/(?P<day>\\d{1,2})/(?P<slug>.*)/$', {})], u'home': [([(u'', [])], u'$', {u'temp
late': u'index.html'})], u'displayable_links_js': [([(u'displayable_links.js', [
])], u'displayable_links.js$', {})], <function blog_post_list at 0x035C89B0>: [(
[(u'blog/', [])], u'blog/$', {}), ([(u'blog/archive/%(year)s/', [u'year'])], u'b
log/archive/(?P<year>\\d{4})/$', {}), ([(u'blog/archive/%(year)s/%(month)s/', [u
'year', u'month'])], u'blog/archive/(?P<year>\\d{4})/(?P<month>\\d{1,2})/$', {})
, ([(u'blog/author/%(username)s/', [u'username'])], u'blog/author/(?P<username>.
*)/$', {}), ([(u'blog/category/%(category)s/', [u'category'])], u'blog/category/
(?P<category>.*)/$', {}), ([(u'blog/tag/%(tag)s/', [u'tag'])], u'blog/tag/(?P<ta
g>.*)/$', {})], <function rename at 0x035EA8B0>: [([(u'admin/media-library/renam
e/', [])], u'admin/media-library/rename/$', {})], <function blog_post_detail at
0x0361B770>: [([(u'blog/%(slug)s/', [u'slug'])], u'blog/(?P<slug>.*)/$', {}), ([
(u'blog/%(year)s/%(slug)s/', [u'year', u'slug'])], u'blog/(?P<year>\\d{4})/(?P<s
lug>.*)/$', {}), ([(u'blog/%(year)s/%(month)s/%(slug)s/', [u'year', u'month', u'
slug'])], u'blog/(?P<year>\\d{4})/(?P<month>\\d{1,2})/(?P<slug>.*)/$', {}), ([(u
'blog/%(year)s/%(month)s/%(day)s/%(slug)s/', [u'year', u'month', u'day', u'slug'
])], u'blog/(?P<year>\\d{4})/(?P<month>\\d{1,2})/(?P<day>\\d{1,2})/(?P<slug>.*)/
$', {})], <function direct_to_template at 0x035B0270>: [([(u'', [])], u'$', {u't
emplate': u'index.html'})], <function rating at 0x035C8870>: [([(u'rating/', [])
], u'rating/$', {})], u'blog_post_detail': [([(u'blog/%(slug)s/', [u'slug'])], u
'blog/(?P<slug>.*)/$', {})], <function displayable_links_js at 0x035B0330>: [([(
u'displayable_links.js', [])], u'displayable_links.js$', {})], <function sitemap
 at 0x035EAB70>: [([(u'sitemap.xml', [])], u'sitemap\\.xml$', {u'sitemaps': {u'a
ll': <class 'mezzanine.core.sitemaps.DisplayableSitemap'>}})], <function mkdir a
t 0x035EA3F0>: [([(u'admin/media-library/mkdir/', [])], u'admin/media-library/mk
dir/', {})], <function search at 0x035B03B0>: [([(u'search/', [])], u'search/$',
 {})], u'blog_post_detail_year': [([(u'blog/%(year)s/%(slug)s/', [u'year', u'slu
g'])], u'blog/(?P<year>\\d{4})/(?P<slug>.*)/$', {})], u'blog_post_list_tag': [([
(u'blog/tag/%(tag)s/', [u'tag'])], u'blog/tag/(?P<tag>.*)/$', {})], u'user_chang
e_password': [([(u'admin/auth/user/%(_0)s/password/', [u'_0'])], u'admin/auth/us
er/(\\d+)/password/$', {})], u'blog_post_list': [([(u'blog/', [])], u'blog/$', {
})], u'blog_post_feed_tag': [([(u'blog/tag/%(tag)s/feeds/%(format)s/', [u'tag',
u'format'])], u'blog/tag/(?P<tag>.*)/feeds/(?P<format>.*)/$', {})], <function bl
og_post_feed at 0x0361BC70>: [([(u'blog/author/%(username)s/feeds/%(format)s/',
[u'username', u'format'])], u'blog/author/(?P<username>.*)/feeds/(?P<format>.*)/
$', {}), ([(u'blog/category/%(category)s/feeds/%(format)s/', [u'category', u'for
mat'])], u'blog/category/(?P<category>.*)/feeds/(?P<format>.*)/$', {}), ([(u'blo
g/tag/%(tag)s/feeds/%(format)s/', [u'tag', u'format'])], u'blog/tag/(?P<tag>.*)/
feeds/(?P<format>.*)/$', {}), ([(u'blog/feeds/%(format)s/', [u'format'])], u'blo
g/feeds/(?P<format>.*)/$', {})], u'fb_browse': [([(u'admin/media-library/browse/
', [])], u'admin/media-library/browse/$', {})], <function admin_keywords_submit
at 0x035C87F0>: [([(u'admin_keywords_submit/', [])], u'admin_keywords_submit/$',
 {})], u'blog_post_feed_author': [([(u'blog/author/%(username)s/feeds/%(format)s
/', [u'username', u'format'])], u'blog/author/(?P<username>.*)/feeds/(?P<format>
.*)/$', {})], u'blog_post_feed_category': [([(u'blog/category/%(category)s/feeds
/%(format)s/', [u'category', u'format'])], u'blog/category/(?P<category>.*)/feed
s/(?P<format>.*)/$', {})], u'search': [([(u'search/', [])], u'search/$', {})], <
function page at 0x02A92CF0>: [([(u'%(slug)s/', [u'slug'])], u'(?P<slug>.*)/$',
{})], <function set_device at 0x035B00B0>: [([(u'set_device/%(device)s/', [u'dev
ice'])], u'set_device/(?P<device>.*)/$', {})], u'password_reset_done': [([(u'pas
sword_reset/done/', [])], u'password_reset/done/$', {})], u'fb_check': [([(u'adm
in/media-library/check_file/', [])], u'admin/media-library/check_file/$', {})],
<function admin_page_ordering at 0x02A92D30>: [([(u'admin_page_ordering/', [])],
 u'admin_page_ordering/$', {})], u'fb_upload': [([(u'admin/media-library/upload/
', [])], u'admin/media-library/upload/', {})], u'blog_post_detail_month': [([(u'
blog/%(year)s/%(month)s/%(slug)s/', [u'year', u'month', u'slug'])], u'blog/(?P<y
ear>\\d{4})/(?P<month>\\d{1,2})/(?P<slug>.*)/$', {})], <function browse at 0x035
EA2F0>: [([(u'admin/media-library/browse/', [])], u'admin/media-library/browse/$
', {})], u'static_proxy': [([(u'asset_proxy/', [])], u'asset_proxy/$', {})], <fu
nction upload at 0x035EA4F0>: [([(u'admin/media-library/upload/', [])], u'admin/
media-library/upload/', {})], <function delete at 0x035EA7B0>: [([(u'admin/media
-library/delete/', [])], u'admin/media-library/delete/$', {})], <function passwo
rd_reset at 0x02A925F0>: [([(u'password_reset/', [])], u'password_reset/$', {})]
, <function set_site at 0x035B0030>: [([(u'set_site/', [])], u'set_site/$', {})]
, u'password_reset_complete': [([(u'reset/done/', [])], u'reset/done/$', {})], <
function edit at 0x035B0430>: [([(u'edit/', [])], u'edit/$', {})], u'blog_post_l
ist_year': [([(u'blog/archive/%(year)s/', [u'year'])], u'blog/archive/(?P<year>\
\d{4})/$', {})], <function javascript_catalog at 0x03571870>: [([(u'jsi18n/%(pac
kages)s/', [u'packages'])], u'jsi18n/(?P<packages>\\S+?)/$', {u'domain': u'djang
o'})], <function password_reset_done at 0x02A92670>: [([(u'password_reset/done/'
, [])], u'password_reset/done/$', {})], u'edit': [([(u'edit/', [])], u'edit/$',
{})], u'password_reset_confirm': [([(u'reset/%(uidb64)s/%(token)s/', [u'uidb64',
 u'token'])], u'reset/(?P<uidb64>[0-9A-Za-z_\\-]+)/(?P<token>.+)/$', {})], <func
tion decorator at 0x035EA670>: [([(u'admin/media-library/upload_file/', [])], u'
admin/media-library/upload_file/$', {})], u'fb_do_upload': [([(u'admin/media-lib
rary/upload_file/', [])], u'admin/media-library/upload_file/$', {})], u'fb_delet
e': [([(u'admin/media-library/delete/', [])], u'admin/media-library/delete/$', {
})], <function <lambda> at 0x035B06F0>: [([(u'admin/media-library/', [])], u'adm
in/media-library/$', {})], u'password_reset': [([(u'password_reset/', [])], u'pa
ssword_reset/$', {})], u'media-library': [([(u'admin/media-library/', [])], u'ad
min/media-library/$', {})], u'blog_post_feed': [([(u'blog/feeds/%(format)s/', [u
'format'])], u'blog/feeds/(?P<format>.*)/$', {})], u'admin_page_ordering': [([(u
'admin_page_ordering/', [])], u'admin_page_ordering/$', {})], u'set_site': [([(u
'set_site/', [])], u'set_site/$', {})], <function password_reset_confirm at 0x02
A927B0>: [([(u'reset/%(uidb64)s/%(token)s/', [u'uidb64', u'token'])], u'reset/(?
P<uidb64>[0-9A-Za-z_\\-]+)/(?P<token>.+)/$', {})], u'page': [([(u'%(slug)s/', [u
'slug'])], u'(?P<slug>.*)/$', {})], <function password_reset_complete at 0x02A92
7F0>: [([(u'reset/done/', [])], u'reset/done/$', {})]}>},
 'app_name': None,
 'callback': None,
 'default_kwargs': {},
 'namespace': None,
 'url_patterns': [<RegexURLResolver <RegexURLPattern list> (None:None) ^admin/>,

<RegexURLPattern home ^$>,
  <RegexURLResolver <module 'mezzanine.urls' from 'c:\python27\lib\site-packages
\mezzanine\urls.pyc'> (None:None) ^>],
 'urlconf_module': <module 'mez.urls' from 'C:\mez\mez\urls.pyc'>,
 'urlconf_name': u'mez.urls'}