Python Progress Bar

Question

How do I use a progress bar when my script is doing some task that is likely to take time?

For example, a function which takes some time to complete and returns

Answer 1

The above suggestions are pretty good, but I think most people just want a ready made solution, with no dependencies on external packages, but is also reusable.

I got the best points of all the above, and made it into a function, along with a test cases.

To use it, just copy the lines under "def update_progress(progress)" but not the test script. Don't forget to import sys. Call this whenever you need to display or update the progress bar.

This works by directly sending the "\r" symbol to console to move cursor back to the start. "print" in python does not recongise the above symbol for this purpose, hence we need 'sys'

import time, sys

# update_progress() : Displays or updates a console progress bar
## Accepts a float between 0 and 1. Any int will be converted to a float.
## A value under 0 represents a 'halt'.
## A value at 1 or bigger represents 100%
def update_progress(progress):
    barLength = 10 # Modify this to change the length of the progress bar
    status = ""
    if isinstance(progress, int):
        progress = float(progress)
    if not isinstance(progress, float):
        progress = 0
        status = "error: progress var must be float\r\n"
    if progress < 0:
        progress = 0
        status = "Halt...\r\n"
    if progress >= 1:
        progress = 1
        status = "Done...\r\n"
    block = int(round(barLength*progress))
    text = "\rPercent: [{0}] {1}% {2}".format( "#"*block + "-"*(barLength-block), progress*100, status)
    sys.stdout.write(text)
    sys.stdout.flush()


# update_progress test script
print "progress : 'hello'"
update_progress("hello")
time.sleep(1)

print "progress : 3"
update_progress(3)
time.sleep(1)

print "progress : [23]"
update_progress([23])
time.sleep(1)

print ""
print "progress : -10"
update_progress(-10)
time.sleep(2)

print ""
print "progress : 10"
update_progress(10)
time.sleep(2)

print ""
print "progress : 0->1"
for i in range(101):
    time.sleep(0.1)
    update_progress(i/100.0)

print ""
print "Test completed"
time.sleep(10)

This is what the result of the test script shows (The last progress bar animates):

progress : 'hello'
Percent: [----------] 0% error: progress var must be float
progress : 3
Percent: [##########] 100% Done...
progress : [23]
Percent: [----------] 0% error: progress var must be float

progress : -10
Percent: [----------] 0% Halt...

progress : 10
Percent: [##########] 100% Done...

progress : 0->1
Percent: [##########] 100% Done...
Test completed