python 图片压缩

'''
pip install pillow
'''
from io import BytesIO

from PIL import Image


def pic_compress(pic_path, out_path, target_size, quality=90, step=5):
    # 读取图片bytes
    with open(pic_path, 'rb') as f:
        pic_byte = f.read()

    current_size = len(pic_byte) / 1024  # 图片当前质量大小
    print("图片压缩前的大小为(KB)：", current_size)
    while current_size > target_size:  # 当达到目标压缩大小后退出循环
        img = Image.open(BytesIO(pic_byte))
        buf = BytesIO()
        img.save(buf, format=img.format, quality=quality)
        pic_byte = buf.getvalue()
        if quality - step < 0:  # 以降低到最小质量
            break
        quality -= step
        current_size = len(pic_byte) / 1024

    # 保存图片
    with open(out_path, 'wb') as f:
        f.write(pic_byte)

    return len(pic_byte) / 1024


def main():
    pic_size = pic_compress('zy.jpg', 'new_zy.jpg', target_size=100)
    print("图片压缩后的大小为(KB)：", pic_size)

if __name__ == '__main__':
    main()