https://github.com/python/cpython/commit/9c93b7402ba11d1d68e856516e56ca72989a7db9
commit: 9c93b7402ba11d1d68e856516e56ca72989a7db9
branch: main
author: Jason R. Coombs <[email protected]>
committer: jaraco <[email protected]>
date: 2024-04-14T11:10:09Z
summary:
gh-117348: restore import time performance of configparser (#117703)
Reduces import time by over 50% (10431µs vs 4350µs on Apple M3 Pro).
files:
A Misc/NEWS.d/next/Library/2024-04-09-20-14-44.gh-issue-117348.A2NAAz.rst
M Lib/configparser.py
diff --git a/Lib/configparser.py b/Lib/configparser.py
index d0326c60e9b907..ff7d712bed4afc 100644
--- a/Lib/configparser.py
+++ b/Lib/configparser.py
@@ -143,17 +143,18 @@
between keys and values are surrounded by spaces.
"""
-from collections.abc import MutableMapping
+# Do not import dataclasses; overhead is unacceptable (gh-117703)
+
+from collections.abc import Iterable, MutableMapping
from collections import ChainMap as _ChainMap
import contextlib
-from dataclasses import dataclass, field
import functools
import io
import itertools
import os
import re
import sys
-from typing import Iterable
+import types
__all__ = ("NoSectionError", "DuplicateOptionError", "DuplicateSectionError",
"NoOptionError", "InterpolationError", "InterpolationDepthError",
@@ -538,21 +539,18 @@ def _interpolate_some(self, parser, option, accum, rest,
section, map,
"found: %r" % (rest,))
-@dataclass
class _ReadState:
- elements_added : set[str] = field(default_factory=set)
+ elements_added : set[str]
cursect : dict[str, str] | None = None
sectname : str | None = None
optname : str | None = None
lineno : int = 0
indent_level : int = 0
- errors : list[ParsingError] = field(default_factory=list)
-
+ errors : list[ParsingError]
-@dataclass
-class _Prefixes:
- full : Iterable[str]
- inline : Iterable[str]
+ def __init__(self):
+ self.elements_added = set()
+ self.errors = list()
class _Line(str):
@@ -560,7 +558,7 @@ class _Line(str):
def __new__(cls, val, *args, **kwargs):
return super().__new__(cls, val)
- def __init__(self, val, prefixes: _Prefixes):
+ def __init__(self, val, prefixes):
self.prefixes = prefixes
@functools.cached_property
@@ -653,7 +651,7 @@ def __init__(self, defaults=None, dict_type=_default_dict,
else:
self._optcre = re.compile(self._OPT_TMPL.format(delim=d),
re.VERBOSE)
- self._prefixes = _Prefixes(
+ self._prefixes = types.SimpleNamespace(
full=tuple(comment_prefixes or ()),
inline=tuple(inline_comment_prefixes or ()),
)
diff --git
a/Misc/NEWS.d/next/Library/2024-04-09-20-14-44.gh-issue-117348.A2NAAz.rst
b/Misc/NEWS.d/next/Library/2024-04-09-20-14-44.gh-issue-117348.A2NAAz.rst
new file mode 100644
index 00000000000000..2451a4e4f622e4
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-04-09-20-14-44.gh-issue-117348.A2NAAz.rst
@@ -0,0 +1,2 @@
+Largely restored import time performance of configparser by avoiding
+dataclasses.
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