Python Progress Bar

Question

Hi everyone!

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 True when done. How can I display a progress bar during the time the function is being executed?

Note that I need this to be in real time, so I can't figure out what to do about it. Do I need a thread for this? I have no idea.

Right now I am not printing anything while the function is being executed, however a project bar would be nice. Also I am more interested in how this can be done from a code point of view.

Answer 1

There are specific libraries (like this one here) but maybe something very simple would do:

import time
import sys

toolbar_width = 40

# setup toolbar
sys.stdout.write("[%s]" % (" " * toolbar_width))
sys.stdout.flush()
sys.stdout.write("\b" * (toolbar_width+1)) # return to start of line, after '['

for i in xrange(toolbar_width):
    time.sleep(0.1) # do real work here
    # update the bar
    sys.stdout.write("-")
    sys.stdout.flush()

sys.stdout.write("\n")

Answer 2

If your work can't be broken down into measurable chunks, you could call your function in a new thread and time how long it takes:

import thread
import time
import sys

def work():
    time.sleep( 5 )

def locked_call( func, lock ):
    lock.acquire()
    func()
    lock.release()

lock = thread.allocate_lock()
thread.start_new_thread( locked_call, ( work, lock, ) )

# This part is icky...
while( not lock.locked() ):
    time.sleep( 0.1 )

while( lock.locked() ):
    sys.stdout.write( "*" )
    sys.stdout.flush()
    time.sleep( 1 )
print "\nWork Done"

You can obviously increase the timing precision as required.

Answer 3

You should link the progress bar to the task at hand (so that it measures the progress :D). For example, if you are FTPing a file, you can tell ftplib to grab a certain size buffer, let's say 128K, and then you add to your progress bar whatever percentage of the filesize 128k represents. If you are using the CLI, and your progress meter is 20 characters long, you would add one character when 1/20th of the file had transferred.

Answer 4

Use this library: fish

Have fun!