python · pablogsal · Feb 16, 2026
diff --git a/Lib/_aix_support.py b/Lib/_aix_support.py
@@ -1,5 +1,8 @@
 """Shared AIX support functions."""
 
+lazy import os
+lazy import contextlib
+
 import sys
 import sysconfig
 
@@ -10,8 +13,6 @@ def _read_cmd_output(commandstring, capture_stderr=False):
     # Similar to os.popen(commandstring, "r").read(),
     # but without actually using os.popen because that
     # function is not usable during python bootstrap.
-    import os
-    import contextlib
     fp = open("/tmp/_aix_support.%s"%(
         os.getpid(),), "w+b")
 

@@ -32,6 +32,9 @@
 #
 #######################################################################
 
+lazy from annotationlib import type_repr
+lazy import warnings
+
 from abc import ABCMeta, abstractmethod
 import sys
 
@@ -485,7 +488,6 @@ def __new__(cls, origin, args):
     def __repr__(self):
         if len(self.__args__) == 2 and _is_param_expr(self.__args__[0]):
             return super().__repr__()
-        from annotationlib import type_repr
         return (f'collections.abc.Callable'
                 f'[[{", ".join([type_repr(a) for a in self.__args__[:-1]])}], '
                 f'{type_repr(self.__args__[-1])}]')
@@ -1064,7 +1066,6 @@ def count(self, value):
 class _DeprecateByteStringMeta(ABCMeta):
     def __new__(cls, name, bases, namespace, **kwargs):
         if name != "ByteString":
-            import warnings
 
             warnings._deprecated(
                 "collections.abc.ByteString",
@@ -1073,7 +1074,6 @@ def __new__(cls, name, bases, namespace, **kwargs):
         return super().__new__(cls, name, bases, namespace, **kwargs)
 
     def __instancecheck__(cls, instance):
-        import warnings
 
         warnings._deprecated(
             "collections.abc.ByteString",
@@ -1170,7 +1170,6 @@ def __iadd__(self, values):
 
 def __getattr__(attr):
     if attr == "ByteString":
-        import warnings
         warnings._deprecated("collections.abc.ByteString", remove=(3, 17))
         globals()["ByteString"] = _deprecated_ByteString
         return _deprecated_ByteString

@@ -1,5 +1,7 @@
 """Shared OS X support functions."""
 
+lazy import contextlib
+
 import os
 import re
 import sys
@@ -58,7 +60,6 @@ def _read_output(commandstring, capture_stderr=False):
     # but without actually using os.popen because that
     # function is not usable during python bootstrap.
     # tempfile is also not available then.
-    import contextlib
     try:
         import tempfile
         fp = tempfile.NamedTemporaryFile()

@@ -1,5 +1,8 @@
 """Pure Python implementation of the datetime module."""
 
+lazy import _strptime
+lazy import warnings
+
 __all__ = ("date", "datetime", "time", "timedelta", "timezone", "tzinfo",
            "MINYEAR", "MAXYEAR", "UTC")
 
@@ -1077,7 +1080,6 @@ def strptime(cls, date_string, format):
         For a list of supported format codes, see the documentation:
             https://docs.python.org/3/library/datetime.html#format-codes
         """
-        import _strptime
         return _strptime._strptime_datetime_date(cls, date_string, format)
 
     # Conversions to string
@@ -1469,7 +1471,6 @@ def strptime(cls, date_string, format):
         For a list of supported format codes, see the documentation:
             https://docs.python.org/3/library/datetime.html#format-codes
         """
-        import _strptime
         return _strptime._strptime_datetime_time(cls, date_string, format)
 
     # Read-only field accessors
@@ -1908,7 +1909,6 @@ def fromtimestamp(cls, timestamp, tz=None):
     @classmethod
     def utcfromtimestamp(cls, t):
         """Construct a naive UTC datetime from a POSIX timestamp."""
-        import warnings
         warnings.warn("datetime.datetime.utcfromtimestamp() is deprecated and scheduled "
                       "for removal in a future version. Use timezone-aware "
                       "objects to represent datetimes in UTC: "
@@ -1926,7 +1926,6 @@ def now(cls, tz=None):
     @classmethod
     def utcnow(cls):
         "Construct a UTC datetime from time.time()."
-        import warnings
         warnings.warn("datetime.datetime.utcnow() is deprecated and scheduled for "
                       "removal in a future version. Use timezone-aware "
                       "objects to represent datetimes in UTC: "
@@ -2217,7 +2216,6 @@ def strptime(cls, date_string, format):
         For a list of supported format codes, see the documentation:
             https://docs.python.org/3/library/datetime.html#format-codes
         """
-        import _strptime
         return _strptime._strptime_datetime_datetime(cls, date_string, format)
 
     def utcoffset(self):

diff --git a/Lib/_pydecimal.py b/Lib/_pydecimal.py
@@ -15,6 +15,9 @@
 
 """Python decimal arithmetic module"""
 
+lazy from itertools import chain as _chain, repeat as _repeat
+lazy from warnings import _deprecated as _warnings_deprecated
+
 __all__ = [
     # Two major classes
     'Decimal', 'Context',
@@ -6279,11 +6282,10 @@ def _group_lengths(grouping):
     #   (2) nonempty list of positive integers + [0]
     #   (3) list of positive integers + [locale.CHAR_MAX], or
 
-    from itertools import chain, repeat
     if not grouping:
         return []
     elif grouping[-1] == 0 and len(grouping) >= 2:
-        return chain(grouping[:-1], repeat(grouping[-2]))
+        return _chain(grouping[:-1], _repeat(grouping[-2]))
     elif grouping[-1] == _locale.CHAR_MAX:
         return grouping[:-1]
     else:
@@ -6405,8 +6407,7 @@ def _format_number(is_negative, intpart, fracpart, exp, spec):
 
 def __getattr__(name):
     if name == "__version__":
-        from warnings import _deprecated
 
-        _deprecated("__version__", remove=(3, 20))
+        _warnings_deprecated("__version__", remove=(3, 20))
         return SPEC_VERSION
     raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
@@ -2,6 +2,8 @@
 Python implementation of the io module.
 """
 
+lazy import warnings
+
 import os
 import abc
 import codecs
@@ -59,7 +61,6 @@ def text_encoding(encoding, stacklevel=2):
         else:
             encoding = "locale"
         if sys.flags.warn_default_encoding:
-            import warnings
             warnings.warn("'encoding' argument not specified.",
                           EncodingWarning, stacklevel + 1)
     return encoding
@@ -225,7 +226,6 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
     if binary and newline is not None:
         raise ValueError("binary mode doesn't take a newline argument")
     if binary and buffering == 1:
-        import warnings
         warnings.warn("line buffering (buffering=1) isn't supported in binary "
                       "mode, the default buffer size will be used",
                       RuntimeWarning, 2)
@@ -283,7 +283,6 @@ def _open_code_with_warning(path):
     in order to allow embedders more control over code files.
     This functionality is not supported on the current runtime.
     """
-    import warnings
     warnings.warn("_pyio.open_code() may not be using hooks",
                   RuntimeWarning, 2)
     return open(path, "rb")
@@ -1530,7 +1529,6 @@ def __init__(self, file, mode='r', closefd=True, opener=None):
             raise TypeError('integer argument expected, got float')
         if isinstance(file, int):
             if isinstance(file, bool):
-                import warnings
                 warnings.warn("bool is used as a file descriptor",
                               RuntimeWarning, stacklevel=2)
                 file = int(file)
@@ -1633,7 +1631,6 @@ def __init__(self, file, mode='r', closefd=True, opener=None):
 
     def _dealloc_warn(self, source):
         if self._fd >= 0 and self._closefd and not self.closed:
-            import warnings
             warnings.warn(f'unclosed file {source!r}', ResourceWarning,
                           stacklevel=2, source=self)
 

diff --git a/Lib/_pylong.py b/Lib/_pylong.py
@@ -12,6 +12,8 @@
 tricky or non-obvious code is not worth it.  For people looking for
 maximum performance, they should use something like gmpy2."""
 
+lazy from decimal import Decimal as D
+
 import re
 import decimal
 try:
@@ -149,7 +151,6 @@ def int_to_decimal(n):
     # "clever" recursive way.  If we want a string representation, we
     # apply str to _that_.
 
-    from decimal import Decimal as D
     BITLIM = 200
 
     # Don't bother caching the "lo" mask in this; the time to compute it is

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+lazy import threading
+
 from dataclasses import dataclass, field
 import traceback
 
@@ -28,7 +30,6 @@ def add(self, s: str) -> None: ...
 
 
 def install_threading_hook(reader: Reader) -> None:
-    import threading
 
     @dataclass
     class ExceptHookHandler:

@@ -20,6 +20,11 @@
 # CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
 from __future__ import annotations
+lazy import signal
+lazy import _sitebuiltins
+lazy from .pager import get_pager
+lazy from site import gethistoryfile
+
 import os
 import time
 
@@ -215,7 +220,6 @@ def do(self) -> None:
 
 class interrupt(FinishCommand):
     def do(self) -> None:
-        import signal
 
         self.reader.console.finish()
         self.reader.finish()
@@ -231,7 +235,6 @@ def do(self) -> None:
 
 class suspend(Command):
     def do(self) -> None:
-        import signal
 
         r = self.reader
         p = r.pos
@@ -446,7 +449,6 @@ def do(self) -> None:
 
 class help(Command):
     def do(self) -> None:
-        import _sitebuiltins
 
         with self.reader.suspend():
             self.reader.msg = _sitebuiltins._Helper()()  # type: ignore[assignment]
@@ -467,8 +469,6 @@ def do(self) -> None:
 
 class show_history(Command):
     def do(self) -> None:
-        from .pager import get_pager
-        from site import gethistoryfile
 
         history = os.linesep.join(self.reader.history[:])
         self.reader.console.restore()

@@ -19,6 +19,8 @@
 
 from __future__ import annotations
 
+lazy import traceback
+
 import _colorize
 
 from abc import ABC, abstractmethod
@@ -170,7 +172,6 @@ def showsyntaxerror(self, filename=None, **kwargs):
         super().showsyntaxerror(filename=filename, **kwargs)
 
     def _excepthook(self, typ, value, tb):
-        import traceback
         lines = traceback.format_exception(
                 typ, value, tb,
                 colorize=self.can_colorize,

@@ -35,6 +35,8 @@
 
 from __future__ import annotations
 
+lazy from .keymap import compile_keymap, parse_keys
+
 from abc import ABC, abstractmethod
 import unicodedata
 from collections import deque
@@ -62,7 +64,6 @@ def empty(self) -> bool:
 class KeymapTranslator(InputTranslator):
     def __init__(self, keymap, verbose=False, invalid_cls=None, character_cls=None):
         self.verbose = verbose
-        from .keymap import compile_keymap, parse_keys
 
         self.keymap = keymap
         self.invalid_cls = invalid_cls

@@ -1,3 +1,8 @@
+lazy from .trace import trace
+lazy import tokenize
+lazy from .console import InteractiveColoredConsole
+lazy from .simple_interact import run_multiline_interactive_console
+
 import errno
 import os
 import sys
@@ -25,7 +30,6 @@
 def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
     if not CAN_USE_PYREPL:
         if not os.getenv('PYTHON_BASIC_REPL') and FAIL_REASON:
-            from .trace import trace
             trace(FAIL_REASON)
             print(FAIL_REASON, file=sys.stderr)
         return sys._baserepl()
@@ -40,7 +44,6 @@ def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
     if pythonstartup and startup_path:
         sys.audit("cpython.run_startup", startup_path)
 
-        import tokenize
         with tokenize.open(startup_path) as f:
             startup_code = compile(f.read(), startup_path, "exec")
             exec(startup_code, namespace)
@@ -52,7 +55,5 @@ def interactive_console(mainmodule=None, quiet=False, pythonstartup=False):
     if not hasattr(sys, "ps2"):
         sys.ps2 = "... "
 
-    from .console import InteractiveColoredConsole
-    from .simple_interact import run_multiline_interactive_console
     console = InteractiveColoredConsole(namespace, filename="<stdin>")
     run_multiline_interactive_console(console)
@@ -1,5 +1,8 @@
 from __future__ import annotations
 
+lazy import tempfile
+lazy import subprocess
+
 import io
 import os
 import re
@@ -41,7 +44,6 @@ def get_pager() -> Pager:
     if hasattr(os, 'system') and os.system('(less) 2>/dev/null') == 0:
         return lambda text, title='': pipe_pager(text, 'less', title)
 
-    import tempfile
     (fd, filename) = tempfile.mkstemp()
     os.close(fd)
     try:
@@ -126,7 +128,6 @@ def plain_pager(text: str, title: str = '') -> None:
 
 def pipe_pager(text: str, cmd: str, title: str = '') -> None:
     """Page through text by feeding it to another program."""
-    import subprocess
     env = os.environ.copy()
     if title:
         title += ' '
@@ -164,7 +165,6 @@ def pipe_pager(text: str, cmd: str, title: str = '') -> None:
 
 def tempfile_pager(text: str, cmd: str, title: str = '') -> None:
     """Page through text by invoking a program on a temporary file."""
-    import tempfile
     with tempfile.TemporaryDirectory() as tempdir:
         filename = os.path.join(tempdir, 'pydoc.out')
         with open(filename, 'w', errors='backslashreplace',