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

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

4 files changed, 25 insertions, 12 deletions

diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index ff7921b520..db62541559 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -1,6 +1,5 @@
 import copy
 import datetime
-from contextlib import suppress
 from decimal import Decimal
 
 from django.core.exceptions import EmptyResultSet, FieldError
@@ -17,9 +16,11 @@ class SQLiteNumericMixin:
     """
     def as_sqlite(self, compiler, connection, **extra_context):
         sql, params = self.as_sql(compiler, connection, **extra_context)
-        with suppress(FieldError):
+        try:
             if self.output_field.get_internal_type() == 'DecimalField':
                 sql = 'CAST(%s AS NUMERIC)' % sql
+        except FieldError:
+            pass
         return sql, params
 
 
diff --git a/django/db/models/options.py b/django/db/models/options.py
index c81a61c916..9f0746bd58 100644
--- a/django/db/models/options.py
+++ b/django/db/models/options.py
@@ -3,7 +3,6 @@ import inspect
 import warnings
 from bisect import bisect
 from collections import OrderedDict, defaultdict
-from contextlib import suppress
 
 from django.apps import apps
 from django.conf import settings
@@ -269,8 +268,10 @@ class Options:
         # is a cached property, and all the models haven't been loaded yet, so
         # we need to make sure we don't cache a string reference.
         if field.is_relation and hasattr(field.remote_field, 'model') and field.remote_field.model:
-            with suppress(AttributeError):
+            try:
                 field.remote_field.model._meta._expire_cache(forward=False)
+            except AttributeError:
+                pass
             self._expire_cache()
         else:
             self._expire_cache(reverse=False)
@@ -518,8 +519,10 @@ class Options:
             # Due to the way Django's internals work, get_field() should also
             # be able to fetch a field by attname. In the case of a concrete
             # field with relation, includes the *_id name too
-            with suppress(AttributeError):
+            try:
                 res[field.attname] = field
+            except AttributeError:
+                pass
         return res
 
     @cached_property
@@ -531,8 +534,10 @@ class Options:
             # Due to the way Django's internals work, get_field() should also
             # be able to fetch a field by attname. In the case of a concrete
             # field with relation, includes the *_id name too
-            with suppress(AttributeError):
+            try:
                 res[field.attname] = field
+            except AttributeError:
+                pass
         return res
 
     def get_field(self, field_name):
@@ -749,10 +754,12 @@ class Options:
         # Creates a cache key composed of all arguments
         cache_key = (forward, reverse, include_parents, include_hidden, topmost_call)
 
-        with suppress(KeyError):
+        try:
             # In order to avoid list manipulation. Always return a shallow copy
             # of the results.
             return self._get_fields_cache[cache_key]
+        except KeyError:
+            pass
 
         fields = []
         # Recursively call _get_fields() on each parent, with the same
diff --git a/django/db/models/query.py b/django/db/models/query.py
index a690ba4b72..42fb728190 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -7,7 +7,6 @@ import operator
 import sys
 import warnings
 from collections import OrderedDict, namedtuple
-from contextlib import suppress
 from functools import lru_cache
 from itertools import chain
 
@@ -521,8 +520,10 @@ class QuerySet:
             return obj, True
         except IntegrityError:
             exc_info = sys.exc_info()
-            with suppress(self.model.DoesNotExist):
+            try:
                 return self.get(**lookup), False
+            except self.model.DoesNotExist:
+                pass
             raise exc_info[0](exc_info[1]).with_traceback(exc_info[2])
 
     def _extract_model_params(self, defaults, **kwargs):
@@ -1337,8 +1338,11 @@ class RawQuerySet:
         # Adjust any column names which don't match field names
         for (query_name, model_name) in self.translations.items():
             # Ignore translations for nonexistent column names
-            with suppress(ValueError):
+            try:
                 index = columns.index(query_name)
+            except ValueError:
+                pass
+            else:
                 columns[index] = model_name
         return columns
 
diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 509d97e65d..017edea873 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -7,7 +7,6 @@ databases). The abstraction barrier only works one way: this module has to know
 all about the internals of models in order to get the information it needs.
 """
 from collections import Counter, Iterator, Mapping, OrderedDict, namedtuple
-from contextlib import suppress
 from itertools import chain, count, product
 from string import ascii_uppercase
 
@@ -313,8 +312,10 @@ class Query:
             obj.subq_aliases = self.subq_aliases.copy()
         obj.used_aliases = self.used_aliases.copy()
         # Clear the cached_property
-        with suppress(AttributeError):
+        try:
             del obj.base_table
+        except AttributeError:
+            pass
         return obj
 
     def chain(self, klass=None):