Python to print out status bar and percentage

Question

To implement a status bar like below:

[==========                ]  45%
[================          ]  60%
[==========================] 100%

I want to this to be printed out to stdout, and keep refreshing it, not print to another line. How to do this?

Answer 1

The ' ' character (carriage return) resets the cursor to the beginning of the line and allows you to write over what was previously on the line.

from time import sleep
import sys

for i in range(21):
    sys.stdout.write('
')
    # the exact output you're looking for:
    sys.stdout.write("[%-20s] %d%%" % ('='*i, 5*i))
    sys.stdout.flush()
    sleep(0.25)

I'm not 100% sure if this is completely portable across all systems, but it works on Linux and OSX at the least.