Defer more imports for even faster CLI

cibuildwheel/__main__.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 __lazy_modules__ = [
     "argparse",
     "cibuildwheel.architecture",
@@ -12,7 +14,6 @@
     "cibuildwheel.util.helpers",
     "cibuildwheel.util.resources",
     "collections",
-    "collections.abc",
     "contextlib",
     "functools",
     "os",
@@ -37,10 +38,8 @@
 import textwrap
 import traceback
 import typing
-from collections.abc import Generator, Iterable, Sequence
 from pathlib import Path
 from tempfile import mkdtemp
-from typing import Any, Literal, TextIO
 
 import cibuildwheel
 import cibuildwheel.util
@@ -56,6 +55,11 @@
 from cibuildwheel.util.helpers import strtobool
 from cibuildwheel.util.resources import read_all_configs
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Generator, Iterable, Sequence
+    from typing import Any, Literal, TextIO
+
 
 @dataclasses.dataclass
 class GlobalOptions:

cibuildwheel/architecture.py

@@ -1,7 +1,7 @@
+from __future__ import annotations
+
 __lazy_modules__ = [
-    "cibuildwheel.typing",
     "collections",
-    "collections.abc",
     "platform",
     "re",
     "shutil",
@@ -15,12 +15,17 @@
 import subprocess
 import sys
 import typing
-from collections.abc import Set
 from enum import StrEnum, auto
-from typing import Final, Literal
+from typing import Final
 
 from cibuildwheel import errors
-from cibuildwheel.typing import PlatformName
+
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Set
+    from typing import Literal
+
+    from cibuildwheel.typing import PlatformName
 
 PRETTY_NAMES: Final[dict[PlatformName, str]] = {
     "linux": "Linux",
@@ -94,7 +99,7 @@ class Architecture(StrEnum):
     x86_64_iphonesimulator = auto()
 
     @staticmethod
-    def parse_config(config: str, platform: PlatformName) -> "set[Architecture]":
+    def parse_config(config: str, platform: PlatformName) -> set[Architecture]:
         result = set()
         for arch_str in re.split(r"[\s,]+", config):
             match arch_str:
@@ -118,7 +123,7 @@ def parse_config(config: str, platform: PlatformName) -> "set[Architecture]":
         return result
 
     @staticmethod
-    def native_arch(platform: PlatformName) -> "Architecture | None":
+    def native_arch(platform: PlatformName) -> Architecture | None:
         native_machine = platform_module.machine()
         native_architecture = Architecture(native_machine)
 
@@ -155,7 +160,7 @@ def native_arch(platform: PlatformName) -> "Architecture | None":
         return native_architecture
 
     @staticmethod
-    def auto_archs(platform: PlatformName) -> "set[Architecture]":
+    def auto_archs(platform: PlatformName) -> set[Architecture]:
         native_arch = Architecture.native_arch(platform)
         if native_arch is None:
             return set()  # can't build anything on this platform
@@ -171,7 +176,7 @@ def auto_archs(platform: PlatformName) -> "set[Architecture]":
         return result
 
     @staticmethod
-    def all_archs(platform: PlatformName) -> "set[Architecture]":
+    def all_archs(platform: PlatformName) -> set[Architecture]:
         all_archs_map = {
             "linux": {
                 Architecture.x86_64,
@@ -195,7 +200,7 @@ def all_archs(platform: PlatformName) -> "set[Architecture]":
         return all_archs_map[platform]
 
     @staticmethod
-    def bitness_archs(platform: PlatformName, bitness: Literal["64", "32"]) -> "set[Architecture]":
+    def bitness_archs(platform: PlatformName, bitness: Literal["64", "32"]) -> set[Architecture]:
         # This map maps 64-bit architectures to their 32-bit equivalents.
         archs_map = {
             Architecture.x86_64: Architecture.i686,

cibuildwheel/environment.py

@@ -1,14 +1,20 @@
-__lazy_modules__ = ["bashlex", "bashlex.errors", "collections", "collections.abc"]
+from __future__ import annotations
+
+__lazy_modules__ = ["bashlex", "bashlex.errors", "collections"]
 
 import dataclasses
-from collections.abc import Mapping, Sequence
-from typing import Any, Protocol
+from typing import Protocol
 
 import bashlex
 import bashlex.errors
 
 from cibuildwheel import bashlex_eval
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
+    from typing import Any
+
 
 class EnvironmentParseError(Exception):
     pass

cibuildwheel/extra.py

@@ -2,9 +2,10 @@
 These are utilities for the `/bin` scripts, not for the `cibuildwheel` program.
 """
 
+from __future__ import annotations
+
 __lazy_modules__ = [
     "collections",
-    "collections.abc",
     "io",
     "json",
     "time",
@@ -18,14 +19,18 @@
 import typing
 import urllib.error
 import urllib.request
-from collections.abc import Mapping, Sequence
 from io import StringIO
-from typing import Any, NotRequired, Protocol
+from typing import NotRequired, Protocol
 
 from cibuildwheel import __version__ as cibw_version
 
 __all__ = ("Printable", "dump_python_configurations")
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
+    from typing import Any
+
 
 class Printable(Protocol):
     def __str__(self) -> str: ...

cibuildwheel/frontend.py

@@ -1,20 +1,24 @@
+from __future__ import annotations
+
 __lazy_modules__ = [
     "cibuildwheel.logger",
     "cibuildwheel.util.helpers",
     "collections",
-    "collections.abc",
     "shlex",
 ]
 
 import dataclasses
 import shlex
 import typing
-from collections.abc import Sequence
 from typing import Literal, Self, get_args
 
 from cibuildwheel.logger import log
 from cibuildwheel.util.helpers import parse_key_value_string
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
 BuildFrontendName = Literal["pip", "build", "build[uv]", "uv"]
 
 

cibuildwheel/logger.py

@@ -1,8 +1,9 @@
+from __future__ import annotations
+
 __lazy_modules__ = [
     "cibuildwheel.ci",
     "codecs",
     "collections",
-    "collections.abc",
     "contextlib",
     "functools",
     "hashlib",
@@ -27,15 +28,18 @@
 import sys
 import textwrap
 import time
-from collections.abc import Generator
 from pathlib import Path
-from typing import IO, TYPE_CHECKING, AnyStr, Final, Literal
+from typing import Final
 
 import humanize
 
 from cibuildwheel.ci import CIProvider, detect_ci_provider, filter_ansi_codes
 
+TYPE_CHECKING = False
 if TYPE_CHECKING:
+    from collections.abc import Generator
+    from typing import IO, AnyStr, Literal
+
     from cibuildwheel.options import Options
 
 FoldPattern = tuple[str, str]
@@ -252,7 +256,7 @@ def error(self, error: BaseException | str) -> None:
             print(f"cibuildwheel: {c.bright_red}error{c.end}: {error}\n", file=sys.stderr)
 
     @contextlib.contextmanager
-    def print_summary(self, *, options: "Options") -> Generator[None, None, None]:
+    def print_summary(self, *, options: Options) -> Generator[None, None, None]:
         start = time.time()
         yield
         duration = time.time() - start
@@ -310,7 +314,7 @@ def _fold_group_identifier(name: str) -> str:
         # lowercase, shorten
         return identifier.lower()[:20]
 
-    def _github_step_summary(self, duration: float, options: "Options") -> str:
+    def _github_step_summary(self, duration: float, options: Options) -> str:
         """
         Returns the GitHub step summary, in markdown format.
         """

cibuildwheel/oci_container.py

@@ -1,12 +1,12 @@
+from __future__ import annotations
+
 __lazy_modules__ = [
     "cibuildwheel.ci",
     "cibuildwheel.errors",
     "cibuildwheel.logger",
-    "cibuildwheel.typing",
     "cibuildwheel.util.cmd",
     "cibuildwheel.util.helpers",
     "collections",
-    "collections.abc",
     "io",
     "json",
     "os",
@@ -17,7 +17,6 @@
     "subprocess",
     "sys",
     "textwrap",
-    "types",
     "uuid",
 ]
 
@@ -33,19 +32,24 @@
 import textwrap
 import typing
 import uuid
-from collections.abc import Mapping, Sequence
 from enum import Enum
 from pathlib import Path, PurePath, PurePosixPath
-from types import TracebackType
-from typing import IO, Literal, Self, assert_never
+from typing import Literal, assert_never
 
 from cibuildwheel.ci import CIProvider, detect_ci_provider
 from cibuildwheel.errors import OCIEngineTooOldError
 from cibuildwheel.logger import log
-from cibuildwheel.typing import PathOrStr
 from cibuildwheel.util.cmd import call
 from cibuildwheel.util.helpers import FlexibleVersion, parse_key_value_string, strtobool
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from collections.abc import Mapping, Sequence
+    from types import TracebackType
+    from typing import IO, Self
+
+    from cibuildwheel.typing import PathOrStr
+
 ContainerEngineName = Literal["docker", "podman"]
 
 
@@ -60,7 +64,7 @@ class OCIPlatform(Enum):
     S390X = "linux/s390x"
 
     @classmethod
-    def native(cls) -> "OCIPlatform":
+    def native(cls) -> OCIPlatform:
         """Return the current OCI platform, or raise ValueError if unknown."""
         arch = platform.machine().lower()
         mapping = {

cibuildwheel/options.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 __lazy_modules__ = [
     "cibuildwheel.architecture",
     "cibuildwheel.environment",
@@ -35,7 +37,7 @@
 import tomllib
 from collections.abc import Callable, Generator, Iterable, Mapping, Sequence, Set
 from pathlib import Path
-from typing import Any, Final, Literal, Self, assert_never
+from typing import Final, assert_never
 
 from packaging.specifiers import SpecifierSet
 
@@ -52,6 +54,10 @@
 from cibuildwheel.util.helpers import format_safe, parse_key_value_string, strtobool, unwrap
 from cibuildwheel.util.packaging import DependencyConstraints
 
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from typing import Any, Literal, Self
+
 MANYLINUX_ARCHS: Final[tuple[str, ...]] = (
     "x86_64",
     "i686",

cibuildwheel/platforms/__init__.py

@@ -3,11 +3,12 @@
 __lazy_modules__ = ["sys"]
 
 import sys
-from typing import TYPE_CHECKING, Final, Protocol
+from typing import Final, Protocol
 
 from cibuildwheel import errors
 from cibuildwheel.platforms import android, ios, linux, macos, pyodide, windows
 
+TYPE_CHECKING = False
 if TYPE_CHECKING:
     from collections.abc import Sequence
     from pathlib import Path