progress.py

#!/usr/bin/env python
# encoding: utf-8
"""
progress_bar.py

From http://code.activestate.com/recipes/168639/.  

Copyright 2002 by Randy Pargman.
Updated 2006, Kelvie Wong.

"""

import sys, time

class bar:
    """ Creates a text-based progress bar. Call the object with the `print'
        command to see the progress bar, which looks something like this:

        [=======>        22%                  ]

        You may specify the progress bar's width, min and max values on init.
    """

    def __init__(self, minValue = 0, maxValue = 100, totalWidth=80):
        self.progBar = "[]"   # This holds the progress bar string
        self.min = minValue
        self.max = maxValue
        self.span = maxValue - minValue
        self.width = totalWidth
        self.amount = 0       # When amount == max, we are 100% done
        self.updateAmount(0)  # Build progress bar string

    def updateAmount(self, newAmount = 0):
        """ Update the progress bar with the new amount (with min and max
            values set at initialization; if it is over or under, it takes the
            min or max value as a default. """
        if newAmount < self.min: newAmount = self.min
        if newAmount > self.max: newAmount = self.max
        self.amount = newAmount

        # Figure out the new percent done, round to an integer
        diffFromMin = float(self.amount - self.min)
        percentDone = (diffFromMin / float(self.span)) * 100.0
        percentDone = int(round(percentDone))

        # Figure out how many hash bars the percentage should be
        allFull = self.width - 2
        numHashes = (percentDone / 100.0) * allFull
        numHashes = int(round(numHashes))

        # Build a progress bar with an arrow of equal signs; special cases for
        # empty and full
        if numHashes == 0:
            self.progBar = "Progress [>%s]" % (' '*(allFull-1))
        elif numHashes == allFull:
            self.progBar = "Progress [%s]" % ('='*allFull)
        else:
            self.progBar = "Progress [%s>%s]" % ('='*(numHashes-1), ' '*(allFull-numHashes))

        # figure out where to put the percentage, roughly centered
        percentPlace = (len(self.progBar) / 2) - len(str(percentDone))
        percentString = str(percentDone) + "%"

        # slice the percentage into the bar
        self.progBar = ''.join([self.progBar[0:percentPlace], percentString,
                                self.progBar[percentPlace+len(percentString):]
                                ])

    def __str__(self):
        return str(self.progBar)

    def __call__(self, value):
        """ Updates the amount, and writes to stdout. Prints a carriage return
            first, so it will overwrite the current line in stdout."""
        print '\r',
        self.updateAmount(value)
        sys.stdout.write(str(self))
        sys.stdout.flush()

#pb = bar(0,126870, 60)
#i = 0
#while i < 126870:
#    if (i+1)%1000 == 0:
#        pb.__call__(i+1)
#        time.sleep(0.01)
#    elif i+1 == 126870:
#        pb.__call__(i+1)
#    i+=1
#print "\n"