Python批量调整10MB以上图片脚本报错排查求助

我编写了Python脚本，用于批量处理指定目录及子目录中大小超过10MB的.png、.jpeg、.jpg格式图片，在Jupyter Notebook中运行时，出现「Unable to resize C:\intersteller\StaticFileBasePath\3.jpg. Skipping.」错误。以下是我的脚本代码及运行结果，请帮忙排查报错根因：

脚本代码 #

from PIL import Image
import os, sys
import PIL
import glob

dir_path = r'C:\intersteller\StaticFileBasePath'

def resize_im(path):
    for foldername, subfolders, photos in os.walk(dir_path):
        for filename in photos:
            if filename.endswith(('jpeg', 'jpg', 'png')) and os.path.getsize(os.path.join(foldername, filename))>10000000:
                        print(foldername + '\\' + filename)
                
                        parent_dir = os.path.dirname(dir_path)
                        img_name = os.path.basename(dir_path).split('.')[0]
                        img_extension = os.path.basename(dir_path).split('.')[1]
                
                        if img_extension.upper() not in ['PNG', 'JPG', 'JPEG']:
                            print('invalid extension >>', img_extension)
                            return
                
                        img = Image.open(dir_path);
                
                        width, height = img.size;
                        asp_rat = width/height;
                
                        # Enter new width (in pixels)
                        new_width = 2775;
                
                        # Enter new height (in pixels)
                        new_height = 3700;
                
                        new_asp_rat = new_width/new_height;
                
                        if (new_asp_rat == asp_rat):
                            img = img.resize((new_width, new_height), Image.ANTIALIAS);
                    
                            # adjusts the height to match the width
                            # NOTE: if you want to adjust the width to the height, instead ->
                            # uncomment the second line (new_width) and comment the first one (new_height)
                        else:
                            new_height = round(new_width / asp_rat);
                            #new_width = round(new_height * asp_rat);
                            img = img.resize((new_width, new_height), Image.ANTIALIAS);
                        
                        if img_extension.upper() == 'PNG':
                            print('png deteced')
                            img.save(os.path.join(parent_dirm + 'new', img_name + 'resized.png'), 'PNG', quality=50)
                        else:
                            img.save(os.path.join(parent_dirm + 'new', img_name + 'resized.jpeg'), 'JPEG', quality=50)

def resize_all(mydir):
    for foldername, subfolders, photos in os.walk(dir_path):
        for filename in photos:
            if filename.endswith(('jpeg', 'jpg', 'png')) and os.path.getsize(os.path.join(foldername, filename))>10000000:
                try:
                    full_path = os.path.join(foldername, filename)
                    resize_im(full_path)
                except Exception as e:
                    print('Unable to resize %s. Skipping.' % full_path)                    

                
if __name__ == '__main__':
    resize_all(dir_path)

运行结果 #

C:\intersteller\StaticFileBasePath\3.jpg
Unable to resize C:\intersteller\StaticFileBasePath\3.jpg. Skipping.
C:\intersteller\StaticFileBasePath\3.jpg
Unable to resize C:\intersteller\StaticFileBasePath\4.jpg. Skipping.

报错根因及修正方案 #

核心错误点 #

1. 函数参数未被使用：resize_im函数接收的path参数完全没用到，反而在函数内部重新遍历根目录dir_path，导致重复触发处理逻辑；且核心的Image.open(dir_path)是尝试打开文件夹而非目标图片，直接引发文件打开错误。
2. 图片信息提取错误：img_name和img_extension错误地从根目录路径提取，而非当前处理的图片文件名——根目录是文件夹，split('.')操作会得到错误结果，甚至引发索引越界。
3. 变量拼写错误：保存路径中使用了未定义的parent_dirm，正确变量应为parent_dir。
4. 保存路径未创建：代码中直接使用parent_dir + 'new'作为保存目录，但该目录若不存在会导致保存失败。
5. 废弃API使用：Image.ANTIALIAS在新版PIL/Pillow中已被废弃，需替换为Image.Resampling.LANCZOS。

修正后的脚本 #

from PIL import Image
import os

dir_path = r'C:\intersteller\StaticFileBasePath'
# 定义保存的目标目录，可根据需求调整
save_dir = os.path.join(os.path.dirname(dir_path), 'resized_images')
os.makedirs(save_dir, exist_ok=True)  # 确保目录存在

def resize_im(img_full_path):
    # 获取图片文件名和扩展名
    filename = os.path.basename(img_full_path)
    img_name, img_extension = os.path.splitext(filename)
    img_extension = img_extension.lstrip('.').upper()

    # 二次校验扩展名（外层已过滤，可选）
    if img_extension not in ['PNG', 'JPG', 'JPEG']:
        print(f'无效扩展名 >> {img_extension}，跳过 {img_full_path}')
        return

    try:
        with Image.open(img_full_path) as img:
            width, height = img.size
            asp_rat = width / height

            new_width = 2775
            new_height = 3700
            new_asp_rat = new_width / new_height

            # 浮点比较避免精度问题，调整尺寸保持原比例
            if not abs(new_asp_rat - asp_rat) < 1e-6:
                new_height = round(new_width / asp_rat)

            # 使用新版调整尺寸API
            resized_img = img.resize((new_width, new_height), Image.Resampling.LANCZOS)

            # 构造保存路径并保存
            if img_extension == 'PNG':
                save_path = os.path.join(save_dir, f'{img_name}_resized.png')
                resized_img.save(save_path, 'PNG', quality=50)
            else:
                save_path = os.path.join(save_dir, f'{img_name}_resized.jpeg')
                resized_img.save(save_path, 'JPEG', quality=50)
            print(f'已处理并保存：{save_path}')
    except Exception as e:
        print(f'处理 {img_full_path} 失败：{str(e)}')

def resize_all(mydir):
    for foldername, _, photos in os.walk(mydir):
        for filename in photos:
            if filename.lower().endswith(('jpeg', 'jpg', 'png')):
                img_full_path = os.path.join(foldername, filename)
                # 检查文件大小是否超过10MB（10*1024*1024=10485760字节）
                if os.path.getsize(img_full_path) > 10485760:
                    resize_im(img_full_path)

if __name__ == '__main__':
    resize_all(dir_path)

内容的提问来源于stack exchange，提问作者kenson kf