progressbar.py

#!/usr/bin/env python
"""
progressbar.py

A Python module with a ProgressBar class which can be used to represent a
task's progress in the form of a progress bar and it can be formated in a
basic way.

Here is some basic usage with the default options:

    >>> from progressbar import ProgressBar
    >>> p = ProgressBar()
    >>> print p
    [>............] 0%
    >>> p + 1
    >>> print p
    [=>...........] 10%
    >>> p + 9
    >>> print p
    [============>] 0%

And here another example with different options:

    >>> from progressbar import ProgressBar
    >>> custom_options = {
    ...     'end': 100, 
    ...     'width': 20, 
    ...     'fill': '#',
    ...     'format': '%(progress)s%% [%(fill)s%(blank)s]'
    ... }
    >>> p = ProgressBar(**custom_options)
    >>> print p
    0% [....................]
    >>> p + 5
    >>> print p
    5% [#...................]
    >>> p + 9
    >>> print p
    100% [####################]
"""
import sys
import time

class ProgressBar(object):
    """ProgressBar class holds the options of the progress bar.
    The options are:
        start   State from which start the progress. For example, if start is 
                5 and the end is 10, the progress of this state is 50%
        end     State in which the progress has terminated.
        width   --
        fill    String to use for "filled" used to represent the progress
        blank   String to use for "filled" used to represent remaining space.
        format  Format
        incremental
    """
    def __init__(self, start=0, end=10, width=12, fill='=', blank='.', format='[%(fill)s>%(blank)s] %(progress)s%%', incremental=True):
        super(ProgressBar, self).__init__()

        self.start = start
        self.end = end
        self.width = width
        self.fill = fill
        self.blank = blank
        self.format = format
        self.incremental = incremental
        self.reset()

    def __add__(self, increment):
        if self.end > self.progress + increment:
            self.progress += increment
        else:
            self.progress = float(self.end)
        return self

    def __sub__(self, decrement):
        if self.start < self.progress - decrement:
            self.progress -= decrement
        else:
            self.progress = float(self.start)
        return self

    def __str__(self):
        cur_width = int(self.progress / self.end * self.width)
        fill = cur_width * self.fill
        blank = (self.width - cur_width) * self.blank
        percentage = int(self.progress / self.end * 100)
        return self.format % {'fill': fill, 'blank': blank, 'progress': percentage}

    __repr__ = __str__

    def reset(self):
        """Resets the current progress to the start point"""
        self.progress = float(self.start)
        return self


class AnimatedProgressBar(ProgressBar):
    """Extends ProgressBar to allow you to use it straighforward on a script.
    Accepts an extra keyword argument named `stdout` (by default use sys.stdout)
    and may be any file-object to which send the progress status.
    """
    def __init__(self, *args, **kwargs):
        super(AnimatedProgressBar, self).__init__(*args, **kwargs)
        self.stdout = kwargs.get('stdout', sys.stdout)

    def show_progress(self):
        if hasattr(self.stdout, 'isatty') and self.stdout.isatty():
            self.stdout.write('\r')
        else:
            self.stdout.write('\n')
        self.stdout.write(str(self))
        self.stdout.flush()


if __name__ == '__main__':
    p = AnimatedProgressBar(end=100, width=80)

    while True:
        p + 5
        p.show_progress()
        time.sleep(0.1)
        if p.progress == 100:
            break
    print #new line