PERF: delay most costly import statement until they are needed

src/inifix/__init__.py

@@ -5,7 +5,9 @@
 from .validation import validate_inifile_schema
 from .format import format_string
 
-from importlib.metadata import version
 
-__version__ = version("inifix")
-del version
+def __getattr__(item: str):
+    if item == "__version__":
+        from importlib.metadata import version
+
+        return version("inifix")

src/inifix/format.py

@@ -1,16 +1,13 @@
 from __future__ import annotations
 
-import argparse
 import os
 import re
 import sys
 import warnings
 from collections.abc import Iterable
-from concurrent.futures import ThreadPoolExecutor
 from difflib import unified_diff
 from functools import partial
 from io import StringIO
-from tempfile import TemporaryDirectory
 from typing import IO, Literal
 
 from inifix._cli import Message, TaskResults, get_cpu_count
@@ -143,7 +140,10 @@ def iniformat(s: str, /) -> str:
 
 
 def main(argv: list[str] | None = None) -> int:
-    parser = argparse.ArgumentParser()
+    from argparse import ArgumentParser
+    from concurrent.futures import ThreadPoolExecutor
+
+    parser = ArgumentParser()
     parser.add_argument("files", nargs="+")
     parser.add_argument(
         "--diff",
@@ -234,6 +234,8 @@ def _format_single_file_cli(
             )
             return TaskResults(status, messages)
 
+        from tempfile import TemporaryDirectory
+
         with TemporaryDirectory(dir=os.path.dirname(file)) as tmpdir:
             tmpfile = os.path.join(tmpdir, "ini")
             with open(tmpfile, "wb") as bfh: