Python：做一个不改图片的尺寸检查器

from __future__ import annotations
import argparse
import struct
from pathlib import Path

PNG_SIGNATURE = b"\x89PNG\r\n\x1a\n"

def read_png_size(path: Path) -> tuple[int, int]:
    with path.open("rb") as handle:
        head = handle.read(24)
    if (len(head) != 24 or head[:8] != PNG_SIGNATURE
            or head[8:12] != b"\x00\x00\x00\x0d"
            or head[12:16] != b"IHDR"):
        raise ValueError("不是可识别的 PNG IHDR 头")
    width, height = struct.unpack(">II", head[16:24])
    if width < 1 or height < 1:
        raise ValueError("宽高必须大于零")
    return width, height

def main() -> int:
    parser = argparse.ArgumentParser(description="只读检查 PNG 宽高")
    parser.add_argument("folder", type=Path)
    args = parser.parse_args()
    if not args.folder.is_dir():
        parser.error("目录不存在或不是目录")
    failures = 0
    found = 0
    for path in sorted(args.folder.iterdir()):
        if not path.is_file() or path.suffix.lower() != ".png":
            continue
        found += 1
        try:
            width, height = read_png_size(path)
            print(f"{path.name}\t{width}×{height}")
        except (OSError, ValueError, struct.error) as exc:
            failures += 1
            print(f"检查失败：{path.name}: {exc}")
    print(f"发现 {found} 张 PNG；失败 {failures} 张；未修改文件")
    return 1 if failures else 0

if __name__ == "__main__":
    raise SystemExit(main())

# 只把目录换成你选择的独立练习素材目录。
python .\check_png.py 'D:\学习实验\png_samples'
$LASTEXITCODE