基于Python实现png转webp的命令行工具

from PIL import Image
import argparse
from pathlib import Path
from concurrent.futures import ThreadPoolExecutor
import os
from time import time


def parse_args():
    """解析命令行参数"""
    parser = argparse.ArgumentParser(description="Convert PNG to WEBP", 
        usage="""
        # 直接执行, 默认转换当前目录下的所有png文件到同级目录
        python main.py

        # 将转换后的webp文件保存到output目录下
        python main.py -o output

        # 转换单个png文件, 单独转换时不支持指定输出目录
        python main.py -f 1.png

        # 同时转换, -t 指定最大并发数, 默认为1, 最大不得超过CPU核心数
        python main.py -t 2

        # 指定图片压缩质量, 默认为80, 取值区间为[0, 100], 值越高, 质量越好, 生成图片体积越大
        python main.py -q 75
        """)
    parser.add_argument(
        "-i", type=str, default=os.getcwd(), help="Path to the input PNG image"
    )
    parser.add_argument(
        "-o", type=str, default=os.getcwd(), help="Path to the output WEBP image"
    )
    parser.add_argument("-f", type=str, default="", help="specific file name")
    parser.add_argument("-t", type=int, default=1, help="Number of threads to use")
    parser.add_argument(
        "-q", type=int, default=80, help="Quality of the output WEBP image"
    )
    return parser.parse_args()


def convert_png_to_webp(input_path: Path, output_path: Path, quality=80) -> None:
    """
    转换PNG为WEBP

    Args:
        input_path (Path): 输入文件路径
        output_path (Path): 输出文件路径, 可以是一个目录, 也可以是一个webp文件的路径
        quality (int, optional): 图片压缩质量. 默认为 80.
    """
    # 如果quality不在0到100之间, 则设置为80
    if quality > 100 or quality < 0:
        print("quality must be between 0 and 100, now set to 80")
    real_q = quality if quality <= 100 and quality > 0 else 80

    # 如果输入文件不存在, 则打印错误信息并返回
    if not input_path.exists():
        print(f"input file {input_path} not found")
        return

    # 如果指定了输出目录, 则尝试创建输出目录
    if not output_path.exists() and output_path.suffix.lower() != ".webp":
        try:
            output_path.mkdir(parents=True)
        except Exception as e:
            print(e)
            print("Failed to create output directory")
            return

    # 如果指定了输出目录, 则修改输出文件名为为输入文件名, 并修改扩展名为.webp
    if output_path.suffix.lower() != ".webp":
        output_path = output_path / input_path.with_suffix(".webp").name
    start = time()
    try:
        with Image.open(input_path) as img:
            print(
                f"Converting {input_path}, quality={real_q}, size: {input_path.stat().st_size / 1024:.2f}KB"
            )
            img.save(output_path, "WEBP", quality=real_q)
            print(
                f"Convert png2webp successfully, output file: {output_path.name}, size: {int(output_path.stat().st_size) / 1024:.2f}KB, elapsed time: {time() - start:.2f}s"
            )
    except Exception as e:
        print(f"Convert png2webp failed: {e}")


def multi_thread_convert(max_workers: int, input_path, output_path, quality) -> None:
    """并发转换png为webp"""
    print(f"convert png to webp with multi threads, max_workers: {max_workers}")
    p = Path(input_path)
    op = Path(output_path) if output_path != os.getcwd() else None
    max_workers = max_workers if max_workers < os.cpu_count() else os.cpu_count()
    with ThreadPoolExecutor(max_workers=max_workers) as executor:
        for f in p.glob("**/*.png"):
            executor.submit(
                convert_png_to_webp, f, op or f.with_suffix(".webp"), quality
            )


def main():
    start = time()
    args = parse_args()
    if not args.f:
        if args.t > 1:
            multi_thread_convert(args.t, args.i, args.o, args.q)
        else:
            p = Path(args.i)
            op = Path(args.o) if args.o != os.getcwd() else None
            for f in p.glob("**/*.png"):
                convert_png_to_webp(f, op or f.with_suffix(".webp"), args.q)
    else:
        p = Path(args.f)
        convert_png_to_webp(p, p.with_suffix(".webp"), args.q)
    print(f"Finished! Total elapsed time: {time() - start:.2f}s")


if __name__ == "__main__":
    main()

python -m venv png2webp

# linux
cd png2webp
source ./bin/activate

# windows powershell
cd png2webp
.\Scripts\activate

python -m pip install pillow pyinstaller

pyinstaller -F --clean .\main.py

png2webp --help

# 直接执行, 默认转换当前目录下的所有png文件到同级目录
png2webp

# 将转换后的webp文件保存到output目录下
png2webp -o output

# 转换单个png文件, 单独转换时不支持指定输出目录
png2webp -f 1.png

# 同时转换, -t 指定最大并发数, 默认为1, 最大不得超过CPU核心数
png2webp -t 2

# 指定图片压缩质量, 默认为80, 取值区间为[0, 100], 值越高, 质量越好, 生成图片体积越大
png2webp -q 75