线程池任务结束程序不会继续执行

res = {}
with ThreadPoolExecutor() as e:
    fs = {}
    for root, dirs, files in os.walk('.'):
        for file in files:
            fs[e.submit(upload_by_file, os.path.join(root, file))] = os.path.splitext(file)[0]

    for f in as_completed(fs):
        try:
            data = f.result()
        except Exception as exc:
            print(f'generated an exception: {exc}, {fs[f]}')
        else:
            res[fs[f]] = data
            print(fs[f], data)

with open('test.json', 'w+', encoding='utf-8') as f:
    json.dump(res, f)

upload_by_file 就是一个上传文件的函数

测试一共 249 个文件, 通过输出可以知道 249 个文件都已经上传完毕, 但是程序并没有执行到保存 json 文件. 而是假死了.

与文件 IO 相关, 代码这么写有时候就会卡住, 而有时候不会.

环境是 Windows 10, Python 3.9