普通工作指示程序运行进度：

python
import time
from tqdm import tqdm
import random
# 使用tqdm提示训练进度
with tqdm(total=1000, desc='i am desc') as pbar:
    for step in range(1000):
        time.sleep(0.1)
        _loss = random.random()
        pbar.set_postfix({'loss': '%.4f' % float(_loss)})
        pbar.update(1)

ftplib 指示文件下载进度：

python
with open(filename, 'wb') as fd:
    total = ftpclient.size(filename)
    with tqdm(total=total) as pbar:
        def callback_(data):
            l = len(data)
            pbar.update(l)
            fd.write(data)
        ftpclient.retrbinary('RETR {}'.format(filename), callback_)