如果你正在开发一个命令行界面，我建议你看看click，它非常好:

import click
import time

for filename in range(3):
    with click.progressbar(range(100), fill_char='=', empty_char=' ') as bar:
        for user in bar:
            time.sleep(0.01)

下面是你得到的输出:

$ python test.py
  [====================================]  100%
  [====================================]  100%
  [=========                           ]   27%

只使用内置的sys:

import sys

def print_progress_bar(index, total, label):
    n_bar = 50  # Progress bar width
    progress = index / total
    sys.stdout.write('\r')
    sys.stdout.write(f"[{'=' * int(n_bar * progress):{n_bar}s}] {int(100 * progress)}%  {label}")
    sys.stdout.flush()

用法:

foo_list = ["a", "b", "c", "d"]
total = len(foo_list)

for index, item in enumerate(foo_list):
    print_progress_bar(index, total, "foo bar")
    sleep(0.5)

Enumerate (foo_list)使您可以在循环期间访问索引值。

输出:

[================================================  ] 96%  foo bar  

要成为纯python并且不进行系统调用:

from time import sleep

for i in range(21):
    spaces = " " * (20 - i)
    percentage = 5*i
    print(f"\r[{'='*i}{spaces}]{percentage}%", flush=True, end="")
    sleep(0.25)

你可以使用\r(回车)。演示:

import sys
total = 10000000
point = total / 100
increment = total / 20
for i in xrange(total):
    if(i % (5 * point) == 0):
        sys.stdout.write("\r[" + "=" * (i / increment) +  " " * ((total - i)/ increment) + "]" +  str(i / point) + "%")
        sys.stdout.flush()

使用@Mark-Rushakoff的答案，我想出了一个更简单的方法，不需要调用sys库。它适用于Python 3。Windows测试:

from time import sleep
for i in range(21):
    # the exact output you're looking for:
    print ("\r[%-20s] %d%%" % ('='*i, 5*i), end='')
    sleep(0.25)

在这里和其他地方的一些答案的基础上，我编写了这个简单的函数，它显示一个进度条和经过/估计的剩余时间。应该在大多数基于unix的机器上运行。

import time
import sys

percent = 50.0
start = time.time()
draw_progress_bar(percent, start)


def draw_progress_bar(percent, start, barLen=20):
sys.stdout.write("\r")
progress = ""
for i in range(barLen):
    if i < int(barLen * percent):
        progress += "="
    else:
        progress += " "

elapsedTime = time.time() - start;
estimatedRemaining = int(elapsedTime * (1.0/percent) - elapsedTime)

if (percent == 1.0):
    sys.stdout.write("[ %s ] %.1f%% Elapsed: %im %02is ETA: Done!\n" % 
        (progress, percent * 100, int(elapsedTime)/60, int(elapsedTime)%60))
    sys.stdout.flush()
    return
else:
    sys.stdout.write("[ %s ] %.1f%% Elapsed: %im %02is ETA: %im%02is " % 
        (progress, percent * 100, int(elapsedTime)/60, int(elapsedTime)%60,
         estimatedRemaining/60, estimatedRemaining%60))
    sys.stdout.flush()
    return