Source code for pycaps.util.progress

import sys
from datetime import datetime, timedelta

def _format_timedelta(td):
    seconds = td.total_seconds()
    hours, seconds = divmod(seconds, 3600)
    minutes, seconds = divmod(seconds, 60)
    return "%d:%02d:%02d" % (hours, minutes, round(seconds))

class ProgressBar(object):
    def __init__(self, descr, n_steps, width=20):
        """
        Create a progress bar object. Doesn't actually start timing or print anything; call initialize() to do that.

        Args:
            descr (str): Description of the task to be performed (e.g. "Loading data: ")
            n_steps (int): Number of steps involved in the task.
            width (int): Width of the progress bar on screen in characters.
        """
        self._descr = descr
        self._progress = 0
        self._n_steps = n_steps
        self._width = width

    def initialize(self):
        """
        Starts timing the task and prints the initial progress bar to the screen.
        """
        self._start_time = datetime.now()
        self._print_bar()

    def is_complete(self):
        """
        Is the task complete?

        Returns: 
            A boolean specifying whether or not the task is complete.
        """
        return self._progress == self._n_steps

    def complete_step(self, print_bar=True):
        """
        Tell a progress bar that one of the tasks is complete.

        Args:
            print_bar (bool): Whether or not to print the bar after this step (defaults to True).
        """
        self.set_step(self._progress + 1, print_bar=print_bar)

    def set_step(self, step, print_bar=True):
        """
        Tell the progress bar that we have completed a certain number of tasks.

        Args:
            step (int): The number of tasks we have completed.
            print_bar (bool): Whether or not to print the bar after this step (defaults to True).
        """
        if step > self._n_steps:
#           print "Warning: Step number %d out of bounds for current progress bar (%d steps max)." % (step, self._n_steps)
            step = self._n_steps

        self._progress = step
        if print_bar:
            self._print_bar()

    def _print_bar(self):
        """
        Print the bar to the screen.
        """
        n_hashes = self._progress * self._width / self._n_steps
        n_spaces = self._width - n_hashes

        completed = "%.1f%%" % (100 * float(self._progress) / self._n_steps)
        completed_pad = " " * (6 - len(completed))
        elapsed = _format_timedelta(datetime.now() - self._start_time)

        sys.stdout.write("\r%s[%s%s] %s%s (%s elapsed)" % (self._descr, "#" * n_hashes, " " * n_spaces, completed, completed_pad, elapsed))
        sys.stdout.flush()
        if self.is_complete():
            print

if __name__ == "__main__":
    import time
    n_steps = 130
    pb = ProgressBar("Loading stuff: ", n_steps, width=40)
    pb.initialize()
    for idx in xrange(n_steps):
        time.sleep(0.1)
        pb.complete_step()