Reverted "Fixed #27818 -- Replaced try/except/pass with contextlib.suppress()."

This reverts commit 550cb3a365dee4edfdd1563224d5304de2a57fda
because try/except performs better.

17 files changed, 72 insertions, 46 deletions

diff --git a/django/contrib/admin/models.py b/django/contrib/admin/models.py
index 4443f13dac..82b3cc0585 100644
--- a/django/contrib/admin/models.py
+++ b/django/contrib/admin/models.py
@@ -1,5 +1,4 @@
 import json
-from contextlib import suppress
 
 from django.conf import settings
 from django.contrib.admin.utils import quote
@@ -138,6 +137,8 @@ class LogEntry(models.Model):
         """
         if self.content_type and self.object_id:
             url_name = 'admin:%s_%s_change' % (self.content_type.app_label, self.content_type.model)
-            with suppress(NoReverseMatch):
+            try:
                 return reverse(url_name, args=(quote(self.object_id),))
+            except NoReverseMatch:
+                pass
         return None
diff --git a/django/contrib/admin/sites.py b/django/contrib/admin/sites.py
index e68dfa1e8b..c0767c15ee 100644
--- a/django/contrib/admin/sites.py
+++ b/django/contrib/admin/sites.py
@@ -1,4 +1,3 @@
-from contextlib import suppress
 from functools import update_wrapper
 from weakref import WeakSet
 
@@ -428,11 +427,15 @@ class AdminSite:
                 'perms': perms,
             }
             if perms.get('change'):
-                with suppress(NoReverseMatch):
+                try:
                     model_dict['admin_url'] = reverse('admin:%s_%s_changelist' % info, current_app=self.name)
+                except NoReverseMatch:
+                    pass
             if perms.get('add'):
-                with suppress(NoReverseMatch):
+                try:
                     model_dict['add_url'] = reverse('admin:%s_%s_add' % info, current_app=self.name)
+                except NoReverseMatch:
+                    pass
 
             if app_label in app_dict:
                 app_dict[app_label]['models'].append(model_dict)
diff --git a/django/contrib/auth/middleware.py b/django/contrib/auth/middleware.py
index 0b3365cb3a..f0102c4455 100644
--- a/django/contrib/auth/middleware.py
+++ b/django/contrib/auth/middleware.py
@@ -1,5 +1,3 @@
-from contextlib import suppress
-
 from django.conf import settings
 from django.contrib import auth
 from django.contrib.auth import load_backend
@@ -91,8 +89,10 @@ class RemoteUserMiddleware(MiddlewareMixin):
         """
         backend_str = request.session[auth.BACKEND_SESSION_KEY]
         backend = auth.load_backend(backend_str)
-        with suppress(AttributeError):  # Backend has no clean_username method.
+        try:
             username = backend.clean_username(username)
+        except AttributeError:  # Backend has no clean_username method.
+            pass
         return username
 
     def _remove_invalid_user(self, request):
diff --git a/django/contrib/contenttypes/fields.py b/django/contrib/contenttypes/fields.py
index 0884089d92..21367c4195 100644
--- a/django/contrib/contenttypes/fields.py
+++ b/django/contrib/contenttypes/fields.py
@@ -1,5 +1,4 @@
 from collections import defaultdict
-from contextlib import suppress
 
 from django.contrib.contenttypes.models import ContentType
 from django.core import checks
@@ -237,8 +236,10 @@ class GenericForeignKey(FieldCacheMixin):
                 rel_obj = None
         if ct_id is not None:
             ct = self.get_content_type(id=ct_id, using=instance._state.db)
-            with suppress(ObjectDoesNotExist):
+            try:
                 rel_obj = ct.get_object_for_this_type(pk=pk_val)
+            except ObjectDoesNotExist:
+                pass
         self.set_cached_value(instance, rel_obj)
         return rel_obj
 
diff --git a/django/contrib/contenttypes/models.py b/django/contrib/contenttypes/models.py
index 066474e49f..ad2e0bc904 100644
--- a/django/contrib/contenttypes/models.py
+++ b/django/contrib/contenttypes/models.py
@@ -1,5 +1,4 @@
 from collections import defaultdict
-from contextlib import suppress
 
 from django.apps import apps
 from django.db import models
@@ -39,8 +38,10 @@ class ContentTypeManager(models.Manager):
         for the same model don't hit the database.
         """
         opts = self._get_opts(model, for_concrete_model)
-        with suppress(KeyError):
+        try:
             return self._get_from_cache(opts)
+        except KeyError:
+            pass
 
         # The ContentType entry was not found in the cache, therefore we
         # proceed to load or create it.
diff --git a/django/contrib/contenttypes/views.py b/django/contrib/contenttypes/views.py
index c527687250..d67f071569 100644
--- a/django/contrib/contenttypes/views.py
+++ b/django/contrib/contenttypes/views.py
@@ -1,5 +1,3 @@
-from contextlib import suppress
-
 from django.apps import apps
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.requests import RequestSite
@@ -55,10 +53,12 @@ def shortcut(request, content_type_id, object_id):
         # First, look for an many-to-many relationship to Site.
         for field in opts.many_to_many:
             if field.remote_field.model is Site:
-                with suppress(IndexError):
+                try:
                     # Caveat: In the case of multiple related Sites, this just
                     # selects the *first* one, which is arbitrary.
                     object_domain = getattr(obj, field.name).all()[0].domain
+                except IndexError:
+                    pass
                 if object_domain is not None:
                     break
 
@@ -77,8 +77,10 @@ def shortcut(request, content_type_id, object_id):
 
         # Fall back to the current site (if possible).
         if object_domain is None:
-            with suppress(Site.DoesNotExist):
+            try:
                 object_domain = Site.objects.get_current(request).domain
+            except Site.DoesNotExist:
+                pass
 
     else:
         # Fall back to the current request's site.
diff --git a/django/contrib/gis/db/backends/spatialite/schema.py b/django/contrib/gis/db/backends/spatialite/schema.py
index 3122b79e7e..6f4e3380db 100644
--- a/django/contrib/gis/db/backends/spatialite/schema.py
+++ b/django/contrib/gis/db/backends/spatialite/schema.py
@@ -1,5 +1,3 @@
-from contextlib import suppress
-
 from django.db.backends.sqlite3.schema import DatabaseSchemaEditor
 from django.db.utils import DatabaseError
 
@@ -91,13 +89,15 @@ class SpatialiteSchemaEditor(DatabaseSchemaEditor):
                 self.remove_geometry_metadata(model, field)
         # Make sure all geom stuff is gone
         for geom_table in self.geometry_tables:
-            with suppress(DatabaseError):
+            try:
                 self.execute(
                     self.sql_discard_geometry_columns % {
                         "geom_table": geom_table,
                         "table": self.quote_name(model._meta.db_table),
                     }
                 )
+            except DatabaseError:
+                pass
         super().delete_model(model, **kwargs)
 
     def add_field(self, model, field):
@@ -138,7 +138,7 @@ class SpatialiteSchemaEditor(DatabaseSchemaEditor):
         super().alter_db_table(model, old_db_table, new_db_table)
         # Repoint any straggler names
         for geom_table in self.geometry_tables:
-            with suppress(DatabaseError):
+            try:
                 self.execute(
                     self.sql_update_geometry_columns % {
                         "geom_table": geom_table,
@@ -146,6 +146,8 @@ class SpatialiteSchemaEditor(DatabaseSchemaEditor):
                         "new_table": self.quote_name(new_db_table),
                     }
                 )
+            except DatabaseError:
+                pass
         # Re-add geometry-ness and rename spatial index tables
         for field in model._meta.local_fields:
             if isinstance(field, GeometryField):
diff --git a/django/contrib/gis/db/models/fields.py b/django/contrib/gis/db/models/fields.py
index 8265815c30..d165313468 100644
--- a/django/contrib/gis/db/models/fields.py
+++ b/django/contrib/gis/db/models/fields.py
@@ -1,5 +1,4 @@
 from collections import defaultdict, namedtuple
-from contextlib import suppress
 
 from django.contrib.gis import forms, gdal
 from django.contrib.gis.db.models.proxy import SpatialProxy
@@ -157,8 +156,10 @@ class BaseSpatialField(Field):
         if isinstance(value, gdal.GDALRaster):
             return value
         elif is_candidate:
-            with suppress(GDALException):
+            try:
                 return gdal.GDALRaster(value)
+            except GDALException:
+                pass
         elif isinstance(value, dict):
             try:
                 return gdal.GDALRaster(value)
diff --git a/django/contrib/gis/gdal/layer.py b/django/contrib/gis/gdal/layer.py
index a2b86c46bd..a2b7fe2211 100644
--- a/django/contrib/gis/gdal/layer.py
+++ b/django/contrib/gis/gdal/layer.py
@@ -1,4 +1,3 @@
-from contextlib import suppress
 from ctypes import byref, c_double
 
 from django.contrib.gis.gdal.base import GDALBase
@@ -77,8 +76,10 @@ class Layer(GDALBase):
         """
         if self._random_read:
             # If the Layer supports random reading, return.
-            with suppress(GDALException):
+            try:
                 return Feature(capi.get_feature(self.ptr, feat_id), self)
+            except GDALException:
+                pass
         else:
             # Random access isn't supported, have to increment through
             # each feature until the given feature ID is encountered.
diff --git a/django/contrib/gis/utils/__init__.py b/django/contrib/gis/utils/__init__.py
index 88de2a4773..800b2dbb89 100644
--- a/django/contrib/gis/utils/__init__.py
+++ b/django/contrib/gis/utils/__init__.py
@@ -1,14 +1,14 @@
 """
  This module contains useful utilities for GeoDjango.
 """
-from contextlib import suppress
-
 from django.contrib.gis.utils.ogrinfo import ogrinfo  # NOQA
 from django.contrib.gis.utils.ogrinspect import mapping, ogrinspect  # NOQA
 from django.contrib.gis.utils.srs import add_srs_entry  # NOQA
 from django.core.exceptions import ImproperlyConfigured
 
-with suppress(ImproperlyConfigured):
+try:
     # LayerMapping requires DJANGO_SETTINGS_MODULE to be set,
     # and ImproperlyConfigured is raised if that's not the case.
     from django.contrib.gis.utils.layermapping import LayerMapping, LayerMapError  # NOQA
+except ImproperlyConfigured:
+    pass
diff --git a/django/contrib/messages/storage/cookie.py b/django/contrib/messages/storage/cookie.py
index 6d5df1af9d..49270cac17 100644
--- a/django/contrib/messages/storage/cookie.py
+++ b/django/contrib/messages/storage/cookie.py
@@ -1,5 +1,4 @@
 import json
-from contextlib import suppress
 
 from django.conf import settings
 from django.contrib.messages.storage.base import BaseStorage, Message
@@ -154,10 +153,12 @@ class CookieStorage(BaseStorage):
         if len(bits) == 2:
             hash, value = bits
             if constant_time_compare(hash, self._hash(value)):
-                with suppress(ValueError):
+                try:
                     # If we get here (and the JSON decode works), everything is
                     # good. In any other case, drop back and return None.
                     return json.loads(value, cls=MessageDecoder)
+                except ValueError:
+                    pass
         # Mark the data as used (so it gets removed) since something was wrong
         # with the data.
         self.used = True
diff --git a/django/contrib/sessions/backends/base.py b/django/contrib/sessions/backends/base.py
index 3ff79b7a39..64955b8bb7 100644
--- a/django/contrib/sessions/backends/base.py
+++ b/django/contrib/sessions/backends/base.py
@@ -1,7 +1,6 @@
 import base64
 import logging
 import string
-from contextlib import suppress
 from datetime import datetime, timedelta
 
 from django.conf import settings
@@ -263,8 +262,10 @@ class SessionBase:
         """
         if value is None:
             # Remove any custom expiration for this session.
-            with suppress(KeyError):
+            try:
                 del self['_session_expiry']
+            except KeyError:
+                pass
             return
         if isinstance(value, timedelta):
             value = timezone.now() + value
diff --git a/django/contrib/sessions/backends/file.py b/django/contrib/sessions/backends/file.py
index 540228b790..0a724f7e0a 100644
--- a/django/contrib/sessions/backends/file.py
+++ b/django/contrib/sessions/backends/file.py
@@ -3,7 +3,6 @@ import logging
 import os
 import shutil
 import tempfile
-from contextlib import suppress
 
 from django.conf import settings
 from django.contrib.sessions.backends.base import (
@@ -156,7 +155,7 @@ class SessionStore(SessionBase):
         # See ticket #8616.
         dir, prefix = os.path.split(session_file_name)
 
-        with suppress(OSError, IOError, EOFError):
+        try:
             output_file_fd, output_file_name = tempfile.mkstemp(dir=dir, prefix=prefix + '_out_')
             renamed = False
             try:
@@ -173,6 +172,8 @@ class SessionStore(SessionBase):
             finally:
                 if not renamed:
                     os.unlink(output_file_name)
+        except (OSError, IOError, EOFError):
+            pass
 
     def exists(self, session_key):
         return os.path.exists(self._key_to_file(session_key))
@@ -182,8 +183,10 @@ class SessionStore(SessionBase):
             if self.session_key is None:
                 return
             session_key = self.session_key
-        with suppress(OSError):
+        try:
             os.unlink(self._key_to_file(session_key))
+        except OSError:
+            pass
 
     def clean(self):
         pass
diff --git a/django/contrib/sitemaps/__init__.py b/django/contrib/sitemaps/__init__.py
index 8f984ae3dc..bd1139ff70 100644
--- a/django/contrib/sitemaps/__init__.py
+++ b/django/contrib/sitemaps/__init__.py
@@ -1,4 +1,3 @@
-from contextlib import suppress
 from urllib.parse import urlencode
 from urllib.request import urlopen
 
@@ -37,9 +36,11 @@ def _get_sitemap_full_url(sitemap_url):
             # First, try to get the "index" sitemap URL.
             sitemap_url = reverse('django.contrib.sitemaps.views.index')
         except NoReverseMatch:
-            with suppress(NoReverseMatch):
+            try:
                 # Next, try for the "global" sitemap URL.
                 sitemap_url = reverse('django.contrib.sitemaps.views.sitemap')
+            except NoReverseMatch:
+                pass
 
     if sitemap_url is None:
         raise SitemapNotFound("You didn't provide a sitemap_url, and the sitemap URL couldn't be auto-detected.")
@@ -88,8 +89,10 @@ class Sitemap:
         if site is None:
             if django_apps.is_installed('django.contrib.sites'):
                 Site = django_apps.get_model('sites.Site')
-                with suppress(Site.DoesNotExist):
+                try:
                     site = Site.objects.get_current()
+                except Site.DoesNotExist:
+                    pass
             if site is None:
                 raise ImproperlyConfigured(
                     "To use sitemaps, either enable the sites framework or pass "
diff --git a/django/contrib/sites/models.py b/django/contrib/sites/models.py
index 9112efbfb5..19f52e4487 100644
--- a/django/contrib/sites/models.py
+++ b/django/contrib/sites/models.py
@@ -1,5 +1,4 @@
 import string
-from contextlib import suppress
 
 from django.core.exceptions import ImproperlyConfigured, ValidationError
 from django.db import models
@@ -108,11 +107,14 @@ def clear_site_cache(sender, **kwargs):
     """
     instance = kwargs['instance']
     using = kwargs['using']
-    with suppress(KeyError):
+    try:
         del SITE_CACHE[instance.pk]
-
-    with suppress(KeyError, Site.DoesNotExist):
+    except KeyError:
+        pass
+    try:
         del SITE_CACHE[Site.objects.using(using).get(pk=instance.pk).domain]
+    except (KeyError, Site.DoesNotExist):
+        pass
 
 
 pre_save.connect(clear_site_cache, sender=Site)
diff --git a/django/contrib/staticfiles/management/commands/collectstatic.py b/django/contrib/staticfiles/management/commands/collectstatic.py
index 7e81ef19ee..e5ae48f9fe 100644
--- a/django/contrib/staticfiles/management/commands/collectstatic.py
+++ b/django/contrib/staticfiles/management/commands/collectstatic.py
@@ -1,6 +1,5 @@
 import os
 from collections import OrderedDict
-from contextlib import suppress
 
 from django.apps import apps
 from django.contrib.staticfiles.finders import get_finders
@@ -313,8 +312,10 @@ class Command(BaseCommand):
         else:
             self.log("Linking '%s'" % source_path, level=1)
             full_path = self.storage.path(prefixed_path)
-            with suppress(OSError):
+            try:
                 os.makedirs(os.path.dirname(full_path))
+            except OSError:
+                pass
             try:
                 if os.path.lexists(full_path):
                     os.unlink(full_path)
diff --git a/django/contrib/syndication/views.py b/django/contrib/syndication/views.py
index f0dcdb3e62..a8b98c84ae 100644
--- a/django/contrib/syndication/views.py
+++ b/django/contrib/syndication/views.py
@@ -1,5 +1,4 @@
 from calendar import timegm
-from contextlib import suppress
 
 from django.conf import settings
 from django.contrib.sites.shortcuts import get_current_site
@@ -153,13 +152,17 @@ class Feed:
 
         title_tmp = None
         if self.title_template is not None:
-            with suppress(TemplateDoesNotExist):
+            try:
                 title_tmp = loader.get_template(self.title_template)
+            except TemplateDoesNotExist:
+                pass
 
         description_tmp = None
         if self.description_template is not None:
-            with suppress(TemplateDoesNotExist):
+            try:
                 description_tmp = loader.get_template(self.description_template)
+            except TemplateDoesNotExist:
+                pass
 
         for item in self._get_dynamic_attr('items', obj):
             context = self.get_context_data(item=item, site=current_site,