progressbar2.py

import time
import progressbar

print('in range')
for i in progressbar.progressbar(range(20)):
    time.sleep(0.02)

print('in list')
my_list = [1]*100
with progressbar.ProgressBar(max_value=len(my_list)) as bar:
    for i,l in enumerate(my_list):
        time.sleep(0.1)
        bar.update(i)

print('unknow len')
bar = progressbar.ProgressBar(max_value=progressbar.UnknownLength)
for i in range(20):
    time.sleep(0.1)
    bar.update(i)