Apr 24, 2025 · Apr 2, 2025 · Apr 4, 2025 · Apr 6, 2025 · Apr 18, 2025 · Apr 18, 2025
diff --git a/Lib/shlex.py b/Lib/shlex.py
 # iterator interface by Gustavo Niemeyer, April 2003.
 # changes to tokenize more like Posix shells by Vinay Sajip, July 2016.

 import os
 import re
 import sys
 from collections import deque

 from io import StringIO

 __all__ = ["shlex", "split", "quote", "join"]
    "A lexical analyzer class for simple shell-like syntaxes."
    def __init__(self, instream=None, infile=None, posix=False,
                 punctuation_chars=False):
        from collections import deque  # deferred import for performance

        if isinstance(instream, str):
            instream = StringIO(instream)
        if instream is not None:

    def sourcehook(self, newfile):
        "Hook called on a filename to be sourced."
        import os.path
        if newfile[0] == '"':
            newfile = newfile[1:-1]
        # This implements cpp-like semantics for relative-path inclusion.
    return ' '.join(quote(arg) for arg in split_command)


 _find_unsafe = re.compile(r'[^\w@%+=:,./-]', re.ASCII).search

 def quote(s):
    """Return a shell-escaped version of the string *s*."""
    if not s:
        return "''"
    if _find_unsafe(s) is None:

    # Use bytes.translate() for performance
    safe_chars = (b'%+,-./0123456789:=@'
                  b'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'
                  b'abcdefghijklmnopqrstuvwxyz')
    # No quoting is needed if `s` is an ASCII string consisting only of `safe_chars`
    if s.isascii() and not s.encode().translate(None, delete=safe_chars):
        return s

    # use single quotes, and put single quotes into double quotes
diff --git a/Lib/test/test_shlex.py b/Lib/test/test_shlex.py
 import shlex
 import string
 import unittest
 from test.support import import_helper


 # The original test data set was from shellwords, by Hartmut Goebel.
        with self.assertRaises(AttributeError):
            shlex_instance.punctuation_chars = False

    def test_lazy_imports(self):
        import_helper.ensure_lazy_imports('shlex', {'collections', 're', 'os'})


 # Allow this test to be used with old shlex.py
 if not getattr(shlex, "split", None):
diff --git a/Misc/NEWS.d/next/Library/2025-04-03-00-56-48.gh-issue-118761.Vb0S1B.rst b/Misc/NEWS.d/next/Library/2025-04-03-00-56-48.gh-issue-118761.Vb0S1B.rst
 Improve import times by up to 33x for the :mod:`shlex` module,
 and improve the performance of :func:`shlex.quote` by up to 12x.
 Patch by Adam Turner.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -7,11 +7,7 @@
		# iterator interface by Gustavo Niemeyer, April 2003.
		# changes to tokenize more like Posix shells by Vinay Sajip, July 2016.

		import os
JelleZijlstra marked this conversation as resolved. Show resolvedHide resolved
		import re
		import sys
		from collections import deque
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		from io import StringIO

		__all__ = ["shlex", "split", "quote", "join"]
Expand All		@@ -20,6 +16,8 @@ class shlex:
		"A lexical analyzer class for simple shell-like syntaxes."
		def __init__(self, instream=None, infile=None, posix=False,
		punctuation_chars=False):
		from collections import deque # deferred import for performance

		if isinstance(instream, str):
		instream = StringIO(instream)
		if instream is not None:
Expand DownExpand Up		@@ -278,6 +276,7 @@ def read_token(self):

		def sourcehook(self, newfile):
		"Hook called on a filename to be sourced."
		import os.path
		if newfile[0] == '"':
		newfile = newfile[1:-1]
		# This implements cpp-like semantics for relative-path inclusion.
Expand DownExpand Up		@@ -318,13 +317,17 @@ def join(split_command):
		return ' '.join(quote(arg) for arg in split_command)


		_find_unsafe = re.compile(r'[^\w@%+=:,./-]', re.ASCII).search

		def quote(s):
		"""Return a shell-escaped version of the string s."""
		if not s:
		return "''"
		if _find_unsafe(s) is None:

		# Use bytes.translate() for performance
		safe_chars = (b'%+,-./0123456789:=@'
		b'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'
		b'abcdefghijklmnopqrstuvwxyz')
		# No quoting is needed if `s` is an ASCII string consisting only of `safe_chars`
		if s.isascii() and not s.encode().translate(None, delete=safe_chars):
		return s

		# use single quotes, and put single quotes into double quotes
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -3,6 +3,7 @@
		import shlex
		import string
		import unittest
		from test.support import import_helper


		# The original test data set was from shellwords, by Hartmut Goebel.
Expand DownExpand Up		@@ -363,6 +364,9 @@ def testPunctuationCharsReadOnly(self):
		with self.assertRaises(AttributeError):
		shlex_instance.punctuation_chars = False

		def test_lazy_imports(self):
		import_helper.ensure_lazy_imports('shlex', {'collections', 're', 'os'})


		# Allow this test to be used with old shlex.py
		if not getattr(shlex, "split", None):
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		Improve import times by up to 33x for the :mod:`shlex` module,
		and improve the performance of :func:`shlex.quote` by up to 12x.
		Patch by Adam Turner.