Source code for pymor.playground.progressbar

#!/usr/bin/env python
# This file is part of the pyMOR project (http://www.pymor.org).
# Copyright 2013-2017 pyMOR developers and contributors. All rights reserved.
# License: BSD 2-Clause License (http://opensource.org/licenses/BSD-2-Clause)

import sys

############################################################
#
# A progress bar that actually shows progress!
#
# Source:
# http://code.activestate.com/recipes/168639-progress-bar-class/
#
############################################################


class ProgressBar:
    """ 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=79):
        self.progBar = "[]"  # This holds the progress bar string
        self.min = minValue
        self.max = maxValue
        self.width = totalWidth
        self.amount = minValue  # When amount == max, we are 100% done
        self.update_amount(self.amount)  # Build progress bar string

    def update_amount(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.max - self.min)) * 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 = "[>%s]" % (' ' * (allFull - 1))
        elif numHashes == allFull:
            self.progBar = "[%s]" % ('=' * allFull)
        else:
            self.progBar = "[%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):
        """ Increases the amount by value, and writes to stdout. Prints a
            carriage return first, so it will overwrite the current line in
            stdout."""
        if self.amount < self.max:
            print('\r', end=' ')
            self.update_amount(self.amount + value)
            sys.stdout.write(str(self))
            sys.stdout.write(self.amount < self.max and "\r" or "\n")
            sys.stdout.flush()

    def setMaximum(self, value):
        self.max = value

    def maximum(self):
        return self.max

if __name__ == '__main__':
    from time import sleep
    p = ProgressBar()
    for i in range(0, 201):
        p(1)
        if i == 90:
            p.max = 200
        sleep(0.02)