https://github.com/python/cpython/commit/ae11d68ab90324a3359699ca13fcf9a229966713 commit: ae11d68ab90324a3359699ca13fcf9a229966713 branch: main author: Jelle Zijlstra <[email protected]> committer: JelleZijlstra <[email protected]> date: 2024-05-28T11:04:08-07:00 summary:
gh-117865: Defer import of re in ast (#119546) This is used only by ast.get_source_segment(), so it seems sensible to avoid importing it. Co-authored-by: Alex Waygood <[email protected]> files: A Misc/NEWS.d/next/Library/2024-05-25-07-25-07.gh-issue-117865.1A0Xpi.rst M Lib/ast.py diff --git a/Lib/ast.py b/Lib/ast.py index bc6c3347787d61..fb4d21b87d8bd0 100644 --- a/Lib/ast.py +++ b/Lib/ast.py @@ -25,7 +25,6 @@ :license: Python License. """ import sys -import re from _ast import * from contextlib import contextmanager, nullcontext from enum import IntEnum, auto, _simple_enum @@ -325,12 +324,18 @@ def get_docstring(node, clean=True): return text -_line_pattern = re.compile(r"(.*?(?:\r\n|\n|\r|$))") +_line_pattern = None def _splitlines_no_ff(source, maxlines=None): """Split a string into lines ignoring form feed and other chars. This mimics how the Python parser splits source code. """ + global _line_pattern + if _line_pattern is None: + # lazily computed to speedup import time of `ast` + import re + _line_pattern = re.compile(r"(.*?(?:\r\n|\n|\r|$))") + lines = [] for lineno, match in enumerate(_line_pattern.finditer(source), 1): if maxlines is not None and lineno > maxlines: diff --git a/Misc/NEWS.d/next/Library/2024-05-25-07-25-07.gh-issue-117865.1A0Xpi.rst b/Misc/NEWS.d/next/Library/2024-05-25-07-25-07.gh-issue-117865.1A0Xpi.rst new file mode 100644 index 00000000000000..48cd390d1bb128 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-05-25-07-25-07.gh-issue-117865.1A0Xpi.rst @@ -0,0 +1,2 @@ +Improve the import time of the :mod:`ast` module by deferring the import of +:mod:`re`. Patch by Jelle Zijlstra. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
