Fixed #30899 -- Lazily compiled import time regular expressions.

django/contrib/admin/utils.py

@@ -1,6 +1,5 @@
 import datetime
 import decimal
-import re
 from collections import defaultdict
 
 from django.core.exceptions import FieldDoesNotExist
@@ -11,12 +10,13 @@ from django.forms.utils import pretty_name
 from django.urls import NoReverseMatch, reverse
 from django.utils import formats, timezone
 from django.utils.html import format_html
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.text import capfirst
 from django.utils.translation import ngettext, override as translation_override
 
 QUOTE_MAP = {i: '_%02X' % i for i in b'":/_#?;@&=+$,"[]<>%\n\\'}
 UNQUOTE_MAP = {v: chr(k) for k, v in QUOTE_MAP.items()}
-UNQUOTE_RE = re.compile('_(?:%s)' % '|'.join([x[1:] for x in UNQUOTE_MAP]))
+UNQUOTE_RE = _lazy_re_compile('_(?:%s)' % '|'.join([x[1:] for x in UNQUOTE_MAP]))
 
 
 class FieldIsAForeignKeyColumnName(Exception):

django/contrib/admindocs/utils.py

@@ -5,6 +5,7 @@ from email.errors import HeaderParseError
 from email.parser import HeaderParser
 
 from django.urls import reverse
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.safestring import mark_safe
 
 try:
@@ -146,8 +147,8 @@ if docutils_is_available:
         create_reference_role(name, urlbase)
 
 # Match the beginning of a named or unnamed group.
-named_group_matcher = re.compile(r'\(\?P(<\w+>)')
-unnamed_group_matcher = re.compile(r'\(')
+named_group_matcher = _lazy_re_compile(r'\(\?P(<\w+>)')
+unnamed_group_matcher = _lazy_re_compile(r'\(')
 
 
 def replace_named_groups(pattern):

django/contrib/gis/db/models/lookups.py

@@ -1,11 +1,10 @@
-import re
-
 from django.contrib.gis.db.models.fields import BaseSpatialField
 from django.contrib.gis.measure import Distance
 from django.db import NotSupportedError
 from django.db.models.expressions import Expression
 from django.db.models.lookups import Lookup, Transform
 from django.db.models.sql.query import Query
+from django.utils.regex_helper import _lazy_re_compile
 
 
 class RasterBandTransform(Transform):
@@ -253,7 +252,7 @@ class OverlapsLookup(GISLookup):
 class RelateLookup(GISLookup):
     lookup_name = 'relate'
     sql_template = '%(func)s(%(lhs)s, %(rhs)s, %%s)'
-    pattern_regex = re.compile(r'^[012TF\*]{9}$')
+    pattern_regex = _lazy_re_compile(r'^[012TF\*]{9}$')
 
     def process_rhs(self, compiler, connection):
         # Check the pattern argument

django/contrib/gis/gdal/libgdal.py

@@ -1,11 +1,11 @@
 import logging
 import os
-import re
 from ctypes import CDLL, CFUNCTYPE, c_char_p, c_int
 from ctypes.util import find_library
 
 from django.contrib.gis.gdal.error import GDALException
 from django.core.exceptions import ImproperlyConfigured
+from django.utils.regex_helper import _lazy_re_compile
 
 logger = logging.getLogger('django.contrib.gis')
 
@@ -83,7 +83,7 @@ def gdal_full_version():
     return _version_info('')
 
 
-version_regex = re.compile(r'^(?P<major>\d+)\.(?P<minor>\d+)(\.(?P<subminor>\d+))?')
+version_regex = _lazy_re_compile(r'^(?P<major>\d+)\.(?P<minor>\d+)(\.(?P<subminor>\d+))?')
 
 
 def gdal_version_info():

django/contrib/gis/geometry.py

@@ -1,13 +1,17 @@
 import re
 
+from django.utils.regex_helper import _lazy_re_compile
+
 # Regular expression for recognizing HEXEWKB and WKT.  A prophylactic measure
 # to prevent potentially malicious input from reaching the underlying C
 # library.  Not a substitute for good Web security programming practices.
-hex_regex = re.compile(r'^[0-9A-F]+$', re.I)
-wkt_regex = re.compile(r'^(SRID=(?P<srid>\-?\d+);)?'
-                       r'(?P<wkt>'
-                       r'(?P<type>POINT|LINESTRING|LINEARRING|POLYGON|MULTIPOINT|'
-                       r'MULTILINESTRING|MULTIPOLYGON|GEOMETRYCOLLECTION)'
-                       r'[ACEGIMLONPSRUTYZ\d,\.\-\+\(\) ]+)$',
-                       re.I)
-json_regex = re.compile(r'^(\s+)?\{.*}(\s+)?$', re.DOTALL)
+hex_regex = _lazy_re_compile(r'^[0-9A-F]+$', re.I)
+wkt_regex = _lazy_re_compile(
+    r'^(SRID=(?P<srid>\-?\d+);)?'
+    r'(?P<wkt>'
+    r'(?P<type>POINT|LINESTRING|LINEARRING|POLYGON|MULTIPOINT|'
+    r'MULTILINESTRING|MULTIPOLYGON|GEOMETRYCOLLECTION)'
+    r'[ACEGIMLONPSRUTYZ\d,\.\-\+\(\) ]+)$',
+    re.I
+)
+json_regex = _lazy_re_compile(r'^(\s+)?\{.*}(\s+)?$', re.DOTALL)

django/core/handlers/wsgi.py

@@ -1,4 +1,3 @@
-import re
 from io import BytesIO
 
 from django.conf import settings
@@ -8,8 +7,9 @@ from django.http import HttpRequest, QueryDict, parse_cookie
 from django.urls import set_script_prefix
 from django.utils.encoding import repercent_broken_unicode
 from django.utils.functional import cached_property
+from django.utils.regex_helper import _lazy_re_compile
 
-_slashes_re = re.compile(br'/+')
+_slashes_re = _lazy_re_compile(br'/+')
 
 
 class LimitedStream:

django/core/management/commands/makemessages.py

@@ -16,10 +16,11 @@ from django.core.management.utils import (
 from django.utils.encoding import DEFAULT_LOCALE_ENCODING
 from django.utils.functional import cached_property
 from django.utils.jslex import prepare_js_for_gettext
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.text import get_text_list
 from django.utils.translation import templatize
 
-plural_forms_re = re.compile(r'^(?P<value>"Plural-Forms.+?\\n")\s*$', re.MULTILINE | re.DOTALL)
+plural_forms_re = _lazy_re_compile(r'^(?P<value>"Plural-Forms.+?\\n")\s*$', re.MULTILINE | re.DOTALL)
 STATUS_OK = 0
 NO_LOCALE_DIR = object()
 

django/core/management/commands/runserver.py

@@ -11,8 +11,9 @@ from django.core.servers.basehttp import (
     WSGIServer, get_internal_wsgi_application, run,
 )
 from django.utils import autoreload
+from django.utils.regex_helper import _lazy_re_compile
 
-naiveip_re = re.compile(r"""^(?:
+naiveip_re = _lazy_re_compile(r"""^(?:
 (?P<addr>
     (?P<ipv4>\d{1,3}(?:\.\d{1,3}){3}) |         # IPv4 address
     (?P<ipv6>\[[a-fA-F0-9:]+\]) |               # IPv6 address

django/core/signing.py

@@ -36,7 +36,6 @@ These functions make use of all of them.
 import base64
 import datetime
 import json
-import re
 import time
 import zlib
 
@@ -45,8 +44,9 @@ from django.utils import baseconv
 from django.utils.crypto import constant_time_compare, salted_hmac
 from django.utils.encoding import force_bytes
 from django.utils.module_loading import import_string
+from django.utils.regex_helper import _lazy_re_compile
 
-_SEP_UNSAFE = re.compile(r'^[A-z0-9-_=]*$')
+_SEP_UNSAFE = _lazy_re_compile(r'^[A-z0-9-_=]*$')
 
 
 class BadSignature(Exception):

django/db/backends/mysql/base.py

@@ -3,14 +3,13 @@ MySQL database backend for Django.
 
 Requires mysqlclient: https://pypi.org/project/mysqlclient/
 """
-import re
-
 from django.core.exceptions import ImproperlyConfigured
 from django.db import utils
 from django.db.backends import utils as backend_utils
 from django.db.backends.base.base import BaseDatabaseWrapper
 from django.utils.asyncio import async_unsafe
 from django.utils.functional import cached_property
+from django.utils.regex_helper import _lazy_re_compile
 
 try:
     import MySQLdb as Database
@@ -47,7 +46,7 @@ django_conversions = {
 
 # This should match the numerical portion of the version numbers (we can treat
 # versions like 5.0.24 and 5.0.24a as the same).
-server_version_re = re.compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
+server_version_re = _lazy_re_compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
 
 
 class CursorWrapper:

django/db/backends/oracle/operations.py

@@ -1,5 +1,4 @@
 import datetime
-import re
 import uuid
 from functools import lru_cache
 
@@ -12,6 +11,7 @@ from django.db.utils import DatabaseError
 from django.utils import timezone
 from django.utils.encoding import force_bytes, force_str
 from django.utils.functional import cached_property
+from django.utils.regex_helper import _lazy_re_compile
 
 from .base import Database
 from .utils import BulkInsertMapper, InsertVar, Oracle_datetime
@@ -102,7 +102,7 @@ END;
     # if the time zone name is passed in parameter. Use interpolation instead.
     # https://groups.google.com/forum/#!msg/django-developers/zwQju7hbG78/9l934yelwfsJ
     # This regexp matches all time zone names from the zoneinfo database.
-    _tzname_re = re.compile(r'^[\w/:+-]+$')
+    _tzname_re = _lazy_re_compile(r'^[\w/:+-]+$')
 
     def _prepare_tzname_delta(self, tzname):
         if '+' in tzname:

django/db/backends/sqlite3/base.py

@@ -23,6 +23,7 @@ from django.utils import timezone
 from django.utils.asyncio import async_unsafe
 from django.utils.dateparse import parse_datetime, parse_time
 from django.utils.duration import duration_microseconds
+from django.utils.regex_helper import _lazy_re_compile
 
 from .client import DatabaseClient                          # isort:skip
 from .creation import DatabaseCreation                      # isort:skip
@@ -380,7 +381,7 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         return self.creation.is_in_memory_db(self.settings_dict['NAME'])
 
 
-FORMAT_QMARK_REGEX = re.compile(r'(?<!%)%s')
+FORMAT_QMARK_REGEX = _lazy_re_compile(r'(?<!%)%s')
 
 
 class SQLiteCursorWrapper(Database.Cursor):

django/db/backends/sqlite3/introspection.py

@@ -7,10 +7,11 @@ from django.db.backends.base.introspection import (
     BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
 )
 from django.db.models.indexes import Index
+from django.utils.regex_helper import _lazy_re_compile
 
 FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('pk',))
 
-field_size_re = re.compile(r'^\s*(?:var)?char\s*\(\s*(\d+)\s*\)\s*$')
+field_size_re = _lazy_re_compile(r'^\s*(?:var)?char\s*\(\s*(\d+)\s*\)\s*$')
 
 
 def get_field_size(name):

django/db/models/sql/constants.py

@@ -2,7 +2,7 @@
 Constants specific to the SQL storage portion of the ORM.
 """
 
-import re
+from django.utils.regex_helper import _lazy_re_compile
 
 # Size of each "chunk" for get_iterator calls.
 # Larger values are slightly faster at the expense of more storage space.
@@ -16,7 +16,7 @@ SINGLE = 'single'
 CURSOR = 'cursor'
 NO_RESULTS = 'no results'
 
-ORDER_PATTERN = re.compile(r'\?|[-+]?[.\w]+$')
+ORDER_PATTERN = _lazy_re_compile(r'\?|[-+]?[.\w]+$')
 ORDER_DIR = {
     'ASC': ('ASC', 'DESC'),
     'DESC': ('DESC', 'ASC'),

django/forms/fields.py

@@ -28,6 +28,7 @@ from django.utils import formats
 from django.utils.dateparse import parse_duration
 from django.utils.duration import duration_string
 from django.utils.ipv6 import clean_ipv6_address
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.translation import gettext_lazy as _, ngettext_lazy
 
 __all__ = (
@@ -243,7 +244,7 @@ class IntegerField(Field):
     default_error_messages = {
         'invalid': _('Enter a whole number.'),
     }
-    re_decimal = re.compile(r'\.0*\s*$')
+    re_decimal = _lazy_re_compile(r'\.0*\s*$')
 
     def __init__(self, *, max_value=None, min_value=None, **kwargs):
         self.max_value, self.min_value = max_value, min_value

django/forms/widgets.py

@@ -4,7 +4,6 @@ HTML Widget classes
 
 import copy
 import datetime
-import re
 import warnings
 from collections import defaultdict
 from itertools import chain
@@ -17,6 +16,7 @@ from django.utils.datastructures import OrderedSet
 from django.utils.dates import MONTHS
 from django.utils.formats import get_format
 from django.utils.html import format_html, html_safe
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.safestring import mark_safe
 from django.utils.topological_sort import (
     CyclicDependencyError, stable_topological_sort,
@@ -935,7 +935,7 @@ class SelectDateWidget(Widget):
     template_name = 'django/forms/widgets/select_date.html'
     input_type = 'select'
     select_widget = Select
-    date_re = re.compile(r'(\d{4}|0)-(\d\d?)-(\d\d?)$')
+    date_re = _lazy_re_compile(r'(\d{4}|0)-(\d\d?)-(\d\d?)$')
 
     def __init__(self, attrs=None, years=None, months=None, empty_label=None):
         self.attrs = attrs or {}

django/http/request.py

@@ -1,7 +1,6 @@
 import cgi
 import codecs
 import copy
-import re
 from io import BytesIO
 from itertools import chain
 from urllib.parse import quote, urlencode, urljoin, urlsplit
@@ -19,9 +18,10 @@ from django.utils.datastructures import (
 from django.utils.encoding import escape_uri_path, iri_to_uri
 from django.utils.functional import cached_property
 from django.utils.http import is_same_domain, limited_parse_qsl
+from django.utils.regex_helper import _lazy_re_compile
 
 RAISE_ERROR = object()
-host_validation_re = re.compile(r"^([a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9\.:]+\])(:\d+)?$")
+host_validation_re = _lazy_re_compile(r"^([a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9\.:]+\])(:\d+)?$")
 
 
 class UnreadablePostError(OSError):

django/http/response.py

@@ -17,8 +17,9 @@ from django.http.cookie import SimpleCookie
 from django.utils import timezone
 from django.utils.encoding import iri_to_uri
 from django.utils.http import http_date
+from django.utils.regex_helper import _lazy_re_compile
 
-_charset_from_content_type_re = re.compile(r';\s*charset=(?P<charset>[^\s;]+)', re.I)
+_charset_from_content_type_re = _lazy_re_compile(r';\s*charset=(?P<charset>[^\s;]+)', re.I)
 
 
 class BadHeaderError(ValueError):

django/middleware/gzip.py

@@ -1,10 +1,9 @@
-import re
-
 from django.utils.cache import patch_vary_headers
 from django.utils.deprecation import MiddlewareMixin
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.text import compress_sequence, compress_string
 
-re_accepts_gzip = re.compile(r'\bgzip\b')
+re_accepts_gzip = _lazy_re_compile(r'\bgzip\b')
 
 
 class GZipMiddleware(MiddlewareMixin):

django/template/base.py

@@ -58,6 +58,7 @@ from inspect import getcallargs, getfullargspec, unwrap
 from django.template.context import BaseContext
 from django.utils.formats import localize
 from django.utils.html import conditional_escape, escape
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.safestring import SafeData, mark_safe
 from django.utils.text import (
     get_text_list, smart_split, unescape_string_literal,
@@ -87,7 +88,7 @@ UNKNOWN_SOURCE = '<unknown source>'
 
 # match a variable or block tag and capture the entire tag, including start/end
 # delimiters
-tag_re = (re.compile('(%s.*?%s|%s.*?%s|%s.*?%s)' %
+tag_re = (_lazy_re_compile('(%s.*?%s|%s.*?%s|%s.*?%s)' %
           (re.escape(BLOCK_TAG_START), re.escape(BLOCK_TAG_END),
            re.escape(VARIABLE_TAG_START), re.escape(VARIABLE_TAG_END),
            re.escape(COMMENT_TAG_START), re.escape(COMMENT_TAG_END))))
@@ -603,7 +604,7 @@ filter_raw_string = r"""
     'arg_sep': re.escape(FILTER_ARGUMENT_SEPARATOR),
 }
 
-filter_re = re.compile(filter_raw_string, re.VERBOSE)
+filter_re = _lazy_re_compile(filter_raw_string, re.VERBOSE)
 
 
 class FilterExpression:
@@ -993,7 +994,7 @@ class VariableNode(Node):
 
 
 # Regex for token keyword arguments
-kwarg_re = re.compile(r"(?:(\w+)=)?(.+)")
+kwarg_re = _lazy_re_compile(r"(?:(\w+)=)?(.+)")
 
 
 def token_kwargs(bits, parser, support_legacy=False):

django/test/client.py

@@ -1,7 +1,6 @@
 import json
 import mimetypes
 import os
-import re
 import sys
 from copy import copy
 from functools import partial
@@ -26,15 +25,16 @@ from django.utils.encoding import force_bytes
 from django.utils.functional import SimpleLazyObject
 from django.utils.http import urlencode
 from django.utils.itercompat import is_iterable
+from django.utils.regex_helper import _lazy_re_compile
 
 __all__ = ('Client', 'RedirectCycleError', 'RequestFactory', 'encode_file', 'encode_multipart')
 
 
 BOUNDARY = 'BoUnDaRyStRiNg'
 MULTIPART_CONTENT = 'multipart/form-data; boundary=%s' % BOUNDARY
-CONTENT_TYPE_RE = re.compile(r'.*; charset=([\w\d-]+);?')
+CONTENT_TYPE_RE = _lazy_re_compile(r'.*; charset=([\w\d-]+);?')
 # Structured suffix spec: https://tools.ietf.org/html/rfc6838#section-4.2.8
-JSON_CONTENT_TYPE_RE = re.compile(r'^application\/(.+\+)?json')
+JSON_CONTENT_TYPE_RE = _lazy_re_compile(r'^application\/(.+\+)?json')
 
 
 class RedirectCycleError(Exception):

django/test/html.py

@@ -1,12 +1,13 @@
 """Compare two HTML documents."""
 
-import re
 from html.parser import HTMLParser
 
+from django.utils.regex_helper import _lazy_re_compile
+
 # ASCII whitespace is U+0009 TAB, U+000A LF, U+000C FF, U+000D CR, or U+0020
 # SPACE.
 # https://infra.spec.whatwg.org/#ascii-whitespace
-ASCII_WHITESPACE = re.compile(r'[\t\n\f\r ]+')
+ASCII_WHITESPACE = _lazy_re_compile(r'[\t\n\f\r ]+')
 
 
 def normalize_whitespace(string):

django/urls/resolvers.py

@@ -21,7 +21,7 @@ from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
 from django.utils.datastructures import MultiValueDict
 from django.utils.functional import cached_property
 from django.utils.http import RFC3986_SUBDELIMS, escape_leading_slashes
-from django.utils.regex_helper import normalize
+from django.utils.regex_helper import _lazy_re_compile, normalize
 from django.utils.translation import get_language
 
 from .converters import get_converter
@@ -195,7 +195,7 @@ class RegexPattern(CheckURLMixin):
         return str(self._regex)
 
 
-_PATH_PARAMETER_COMPONENT_RE = re.compile(
+_PATH_PARAMETER_COMPONENT_RE = _lazy_re_compile(
     r'<(?:(?P<converter>[^>:]+):)?(?P<parameter>\w+)>'
 )
 

django/utils/cache.py

@@ -17,7 +17,6 @@ An example: i18n middleware would need to distinguish caches by the
 "Accept-language" header.
 """
 import hashlib
-import re
 import time
 from collections import defaultdict
 
@@ -29,10 +28,11 @@ from django.utils.http import (
     http_date, parse_etags, parse_http_date_safe, quote_etag,
 )
 from django.utils.log import log_response
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.timezone import get_current_timezone_name
 from django.utils.translation import get_language
 
-cc_delim_re = re.compile(r'\s*,\s*')
+cc_delim_re = _lazy_re_compile(r'\s*,\s*')
 
 
 def patch_cache_control(response, **kwargs):

django/utils/dateformat.py

@@ -12,17 +12,17 @@ Usage:
 """
 import calendar
 import datetime
-import re
 import time
 
 from django.utils.dates import (
     MONTHS, MONTHS_3, MONTHS_ALT, MONTHS_AP, WEEKDAYS, WEEKDAYS_ABBR,
 )
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.timezone import get_default_timezone, is_aware, is_naive
 from django.utils.translation import gettext as _
 
-re_formatchars = re.compile(r'(?<!\\)([aAbBcdDeEfFgGhHiIjlLmMnNoOPrsStTUuwWyYzZ])')
-re_escaped = re.compile(r'\\(.)')
+re_formatchars = _lazy_re_compile(r'(?<!\\)([aAbBcdDeEfFgGhHiIjlLmMnNoOPrsStTUuwWyYzZ])')
+re_escaped = _lazy_re_compile(r'\\(.)')
 
 
 class Formatter:

django/utils/dateparse.py

@@ -6,27 +6,27 @@
 # - The date/datetime/time constructors produce friendlier error messages.
 
 import datetime
-import re
 
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.timezone import get_fixed_timezone, utc
 
-date_re = re.compile(
+date_re = _lazy_re_compile(
     r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})$'
 )
 
-time_re = re.compile(
+time_re = _lazy_re_compile(
     r'(?P<hour>\d{1,2}):(?P<minute>\d{1,2})'
     r'(?::(?P<second>\d{1,2})(?:\.(?P<microsecond>\d{1,6})\d{0,6})?)?'
 )
 
-datetime_re = re.compile(
+datetime_re = _lazy_re_compile(
     r'(?P<year>\d{4})-(?P<month>\d{1,2})-(?P<day>\d{1,2})'
     r'[T ](?P<hour>\d{1,2}):(?P<minute>\d{1,2})'
     r'(?::(?P<second>\d{1,2})(?:\.(?P<microsecond>\d{1,6})\d{0,6})?)?'
     r'(?P<tzinfo>Z|[+-]\d{2}(?::?\d{2})?)?$'
 )
 
-standard_duration_re = re.compile(
+standard_duration_re = _lazy_re_compile(
     r'^'
     r'(?:(?P<days>-?\d+) (days?, )?)?'
     r'(?P<sign>-?)'
@@ -39,7 +39,7 @@ standard_duration_re = re.compile(
 
 # Support the sections of ISO 8601 date representation that are accepted by
 # timedelta
-iso8601_duration_re = re.compile(
+iso8601_duration_re = _lazy_re_compile(
     r'^(?P<sign>[-+]?)'
     r'P'
     r'(?:(?P<days>\d+(.\d+)?)D)?'
@@ -54,7 +54,7 @@ iso8601_duration_re = re.compile(
 # Support PostgreSQL's day-time interval format, e.g. "3 days 04:05:06". The
 # year-month and mixed intervals cannot be converted to a timedelta and thus
 # aren't accepted.
-postgres_interval_re = re.compile(
+postgres_interval_re = _lazy_re_compile(
     r'^'
     r'(?:(?P<days>-?\d+) (days? ?))?'
     r'(?:(?P<sign>[-+])?'

django/utils/datetime_safe.py

@@ -7,12 +7,13 @@
 # >>> datetime_safe.date(10, 8, 2).strftime("%Y/%m/%d was a %A")
 # '0010/08/02 was a Monday'
 
-import re
 import time as ttime
 from datetime import (
     date as real_date, datetime as real_datetime, time as real_time,
 )
 
+from django.utils.regex_helper import _lazy_re_compile
+
 
 class date(real_date):
     def strftime(self, fmt):
@@ -54,7 +55,7 @@ def new_datetime(d):
 
 # This library does not support strftime's "%s" or "%y" format strings.
 # Allowed if there's an even number of "%"s because they are escaped.
-_illegal_formatting = re.compile(r"((^|[^%])(%%)*%[sy])")
+_illegal_formatting = _lazy_re_compile(r"((^|[^%])(%%)*%[sy])")
 
 
 def _findall(text, substr):

django/utils/html.py

@@ -11,6 +11,7 @@ from urllib.parse import (
 from django.utils.encoding import punycode
 from django.utils.functional import Promise, keep_lazy, keep_lazy_text
 from django.utils.http import RFC3986_GENDELIMS, RFC3986_SUBDELIMS
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.safestring import SafeData, SafeString, mark_safe
 from django.utils.text import normalize_newlines
 
@@ -21,10 +22,13 @@ WRAPPING_PUNCTUATION = [('(', ')'), ('[', ']')]
 # List of possible strings used for bullets in bulleted lists.
 DOTS = ['·', '*', '\u2022', '•', '•', '•']
 
-unencoded_ampersands_re = re.compile(r'&(?!(\w+|#\d+);)')
-word_split_re = re.compile(r'''([\s<>"']+)''')
-simple_url_re = re.compile(r'^https?://\[?\w', re.IGNORECASE)
-simple_url_2_re = re.compile(r'^www\.|^(?!http)\w[^@]+\.(com|edu|gov|int|mil|net|org)($|/.*)$', re.IGNORECASE)
+unencoded_ampersands_re = _lazy_re_compile(r'&(?!(\w+|#\d+);)')
+word_split_re = _lazy_re_compile(r'''([\s<>"']+)''')
+simple_url_re = _lazy_re_compile(r'^https?://\[?\w', re.IGNORECASE)
+simple_url_2_re = _lazy_re_compile(
+    r'^www\.|^(?!http)\w[^@]+\.(com|edu|gov|int|mil|net|org)($|/.*)$',
+    re.IGNORECASE
+)
 
 
 @keep_lazy(str, SafeString)

django/utils/http.py

@@ -16,9 +16,10 @@ from django.core.exceptions import TooManyFieldsSent
 from django.utils.datastructures import MultiValueDict
 from django.utils.deprecation import RemovedInDjango40Warning
 from django.utils.functional import keep_lazy_text
+from django.utils.regex_helper import _lazy_re_compile
 
 # based on RFC 7232, Appendix C
-ETAG_MATCH = re.compile(r'''
+ETAG_MATCH = _lazy_re_compile(r'''
     \A(      # start of string and capture group
     (?:W/)?  # optional weak indicator
     "        # opening quote
@@ -34,14 +35,14 @@ __M = r'(?P<mon>\w{3})'
 __Y = r'(?P<year>\d{4})'
 __Y2 = r'(?P<year>\d{2})'
 __T = r'(?P<hour>\d{2}):(?P<min>\d{2}):(?P<sec>\d{2})'
-RFC1123_DATE = re.compile(r'^\w{3}, %s %s %s %s GMT$' % (__D, __M, __Y, __T))
-RFC850_DATE = re.compile(r'^\w{6,9}, %s-%s-%s %s GMT$' % (__D, __M, __Y2, __T))
-ASCTIME_DATE = re.compile(r'^\w{3} %s %s %s %s$' % (__M, __D2, __T, __Y))
+RFC1123_DATE = _lazy_re_compile(r'^\w{3}, %s %s %s %s GMT$' % (__D, __M, __Y, __T))
+RFC850_DATE = _lazy_re_compile(r'^\w{6,9}, %s-%s-%s %s GMT$' % (__D, __M, __Y2, __T))
+ASCTIME_DATE = _lazy_re_compile(r'^\w{3} %s %s %s %s$' % (__M, __D2, __T, __Y))
 
 RFC3986_GENDELIMS = ":/?#[]@"
 RFC3986_SUBDELIMS = "!$&'()*+,;="
 
-FIELDS_MATCH = re.compile('[&;]')
+FIELDS_MATCH = _lazy_re_compile('[&;]')
 
 
 @keep_lazy_text

django/utils/text.py

@@ -7,6 +7,7 @@ from io import BytesIO
 
 from django.utils.deprecation import RemovedInDjango40Warning
 from django.utils.functional import SimpleLazyObject, keep_lazy_text, lazy
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.translation import gettext as _, gettext_lazy, pgettext
 
 
@@ -17,11 +18,11 @@ def capfirst(x):
 
 
 # Set up regular expressions
-re_words = re.compile(r'<[^>]+?>|([^<>\s]+)', re.S)
-re_chars = re.compile(r'<[^>]+?>|(.)', re.S)
-re_tag = re.compile(r'<(/)?(\S+?)(?:(\s*/)|\s.*?)?>', re.S)
-re_newlines = re.compile(r'\r\n|\r')  # Used in normalize_newlines
-re_camel_case = re.compile(r'(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|$)))')
+re_words = _lazy_re_compile(r'<[^>]+?>|([^<>\s]+)', re.S)
+re_chars = _lazy_re_compile(r'<[^>]+?>|(.)', re.S)
+re_tag = _lazy_re_compile(r'<(/)?(\S+?)(?:(\s*/)|\s.*?)?>', re.S)
+re_newlines = _lazy_re_compile(r'\r\n|\r')  # Used in normalize_newlines
+re_camel_case = _lazy_re_compile(r'(((?<=[a-z])[A-Z])|([A-Z](?![A-Z]|$)))')
 
 
 @keep_lazy_text
@@ -306,7 +307,7 @@ def compress_sequence(sequence):
 
 # Expression to match some_token and some_token="with spaces" (and similarly
 # for single-quoted strings).
-smart_split_re = re.compile(r"""
+smart_split_re = _lazy_re_compile(r"""
     ((?:
         [^\s'"]*
         (?:
@@ -355,7 +356,7 @@ def _replace_entity(match):
             return match.group(0)
 
 
-_entity_re = re.compile(r"&(#?[xX]?(?:[0-9a-fA-F]+|\w{1,8}));")
+_entity_re = _lazy_re_compile(r"&(#?[xX]?(?:[0-9a-fA-F]+|\w{1,8}));")
 
 
 @keep_lazy_text

django/utils/translation/__init__.py

@@ -1,7 +1,6 @@
 """
 Internationalization support.
 """
-import re
 import warnings
 from contextlib import ContextDecorator
 from decimal import ROUND_UP, Decimal
@@ -9,6 +8,7 @@ from decimal import ROUND_UP, Decimal
 from django.utils.autoreload import autoreload_started, file_changed
 from django.utils.deprecation import RemovedInDjango40Warning
 from django.utils.functional import lazy
+from django.utils.regex_helper import _lazy_re_compile
 
 __all__ = [
     'activate', 'deactivate', 'override', 'deactivate_all',
@@ -328,7 +328,7 @@ def get_language_info(lang_code):
     return info
 
 
-trim_whitespace_re = re.compile(r'\s*\n\s*')
+trim_whitespace_re = _lazy_re_compile(r'\s*\n\s*')
 
 
 def trim_whitespace(s):

django/utils/translation/template.py

@@ -1,12 +1,12 @@
-import re
 import warnings
 from io import StringIO
 
 from django.template.base import TRANSLATOR_COMMENT_MARK, Lexer, TokenType
+from django.utils.regex_helper import _lazy_re_compile
 
 from . import TranslatorCommentWarning, trim_whitespace
 
-dot_re = re.compile(r'\S')
+dot_re = _lazy_re_compile(r'\S')
 
 
 def blankout(src, char):
@@ -17,8 +17,8 @@ def blankout(src, char):
     return dot_re.sub(char, src)
 
 
-context_re = re.compile(r"""^\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?'))\s*""")
-inline_re = re.compile(
+context_re = _lazy_re_compile(r"""^\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?'))\s*""")
+inline_re = _lazy_re_compile(
     # Match the trans 'some text' part
     r"""^\s*trans\s+((?:"[^"]*?")|(?:'[^']*?'))"""
     # Match and ignore optional filters
@@ -26,10 +26,10 @@ inline_re = re.compile(
     # Match the optional context part
     r"""(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?\s*"""
 )
-block_re = re.compile(r"""^\s*blocktrans(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?(?:\s+|$)""")
-endblock_re = re.compile(r"""^\s*endblocktrans$""")
-plural_re = re.compile(r"""^\s*plural$""")
-constant_re = re.compile(r"""_\(((?:".*?")|(?:'.*?'))\)""")
+block_re = _lazy_re_compile(r"""^\s*blocktrans(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?(?:\s+|$)""")
+endblock_re = _lazy_re_compile(r"""^\s*endblocktrans$""")
+plural_re = _lazy_re_compile(r"""^\s*plural$""")
+constant_re = _lazy_re_compile(r"""_\(((?:".*?")|(?:'.*?'))\)""")
 
 
 def templatize(src, origin=None):

django/utils/translation/trans_real.py

@@ -14,6 +14,7 @@ from django.conf.locale import LANG_INFO
 from django.core.exceptions import AppRegistryNotReady
 from django.core.signals import setting_changed
 from django.dispatch import receiver
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.safestring import SafeData, mark_safe
 
 from . import to_language, to_locale
@@ -31,18 +32,18 @@ CONTEXT_SEPARATOR = "\x04"
 
 # Format of Accept-Language header values. From RFC 2616, section 14.4 and 3.9
 # and RFC 3066, section 2.1
-accept_language_re = re.compile(r'''
+accept_language_re = _lazy_re_compile(r'''
         ([A-Za-z]{1,8}(?:-[A-Za-z0-9]{1,8})*|\*)      # "en", "en-au", "x-y-z", "es-419", "*"
         (?:\s*;\s*q=(0(?:\.\d{,3})?|1(?:\.0{,3})?))?  # Optional "q=1.00", "q=0.8"
         (?:\s*,\s*|$)                                 # Multiple accepts per header.
         ''', re.VERBOSE)
 
-language_code_re = re.compile(
+language_code_re = _lazy_re_compile(
     r'^[a-z]{1,8}(?:-[a-z0-9]{1,8})*(?:@[a-z0-9]{1,20})?$',
     re.IGNORECASE
 )
 
-language_code_prefix_re = re.compile(r'^/(\w+([@-]\w+)?)(/|$)')
+language_code_prefix_re = _lazy_re_compile(r'^/(\w+([@-]\w+)?)(/|$)')
 
 
 @receiver(setting_changed)

django/views/debug.py

@@ -13,6 +13,7 @@ from django.utils import timezone
 from django.utils.datastructures import MultiValueDict
 from django.utils.encoding import force_str
 from django.utils.module_loading import import_string
+from django.utils.regex_helper import _lazy_re_compile
 from django.utils.version import get_docs_version
 
 # Minimal Django templates engine to render the error templates
@@ -24,7 +25,7 @@ DEBUG_ENGINE = Engine(
     libraries={'i18n': 'django.templatetags.i18n'},
 )
 
-HIDDEN_SETTINGS = re.compile('API|TOKEN|KEY|SECRET|PASS|SIGNATURE', flags=re.IGNORECASE)
+HIDDEN_SETTINGS = _lazy_re_compile('API|TOKEN|KEY|SECRET|PASS|SIGNATURE', flags=re.IGNORECASE)
 
 CLEANSED_SUBSTITUTE = '********************'