Source code for bag.show_progress

"""2 solutions for showing progress periodically on the console.

To use them, encapsulate your iterable with these generators.

When you know how many items you're going to process, you can print the
percentage done and the time remaining. Otherwise, you can only print the
iteration index. The output messages are configurable; here are examples::

    $ python -c "from bag.show_progress import *; test_percentage()"
    7.0% done, 0:00:53 left...
    15.0% done, 0:00:45 left...
    23.0% done, 0:00:40 left...
    31.0% done, 0:00:35 left...
    39.0% done, 0:00:31 left...
    47.0% done, 0:00:27 left...
    55.0% done, 0:00:22 left...
    63.0% done, 0:00:18 left...
    71.0% done, 0:00:14 left...
    79.0% done, 0:00:10 left...
    87.0% done, 0:00:06 left...
    95.0% done, 0:00:02 left...

    $ python -c "from bag.show_progress import *; test_progress()"
    Item #17 done. Working...
    Item #34 done. Working...
    Item #51 done. Working...
    Item #68 done. Working...
    Item #85 done. Working...
    Done in 0:00:23.726902! Total items: 100

Both solutions decide when to print out a progress message based on time, not
on the number of iterations, so updates tend to appear steadily on the screen.
"""

from datetime import datetime, timedelta


[docs]class ShowingProgress: """A generator that encapsulates your iterable. It prints the progress every so many seconds. Usage:: p = ShowingProgress(iterable, seconds=6) # Then use p instead of your iterable: for index, something in p: process(something) """ def __init__(self, iterable, message='Item #{} done. Working...', seconds=6, done='Done in {time}! Total items: {total}'): self.iterable = iterable self.seconds = timedelta(0, seconds) self.message = message self.done = done def __iter__(self): utcnow = datetime.utcnow seconds = self.seconds started = printed = utcnow() for index, o in enumerate(self.iterable, 1): # Start counting at 1 yield index, o if seconds > utcnow() - printed: continue print(self.message.format(index)) printed = utcnow() if self.done: print(self.done.format(total=index, time=utcnow() - started))
[docs]class PercentageDone: """When you are processing a long iterable and it takes minutes, you should let the user know that your application is still working. This class helps do that in the console, without creating too much output. """ def __init__(self, max, granularity=6): """Parameters: *max*: The number of elements that shall be processed. *granularity*: how many seconds must elapse between printing the percentage done. """ self.max = int(max) self.granularity = timedelta(0, granularity) self.current = 0 self.start = self.printed = datetime.utcnow()
[docs] def calc(self, val): """Takes *val* (the current position relative to *max* and calculates: * self.current (int): the current percentage done * self.delta (timedelta): time elapsed since self.start * self.estimate (timedelta): how long this is going to take (total) * self.remaining (timedelta): how long you still have to wait Returns self.remaining. """ percent = 100 * int(val) / self.max if percent > self.current: self.current = percent self.delta = datetime.utcnow() - self.start self.estimate = timedelta(0, 100 * self.delta.seconds / percent) self.remaining = self.estimate - self.delta if self.remaining < timedelta(0): self.remaining = timedelta(0) return self.remaining
[docs] def display(self, val): """Calls self.calc() and prints the percentage done and how long the user still has to wait. But only does so every X seconds, where X is *granularity*. Does nothing if the granularity has not elapsed yet. """ if self.granularity > datetime.utcnow() - self.printed: return remaining = self.calc(val) if not remaining: return print('{0}% done, {1} left...'.format( self.current, str(remaining)[:7])) self.printed = datetime.utcnow()
[docs]class ShowingPercentage(PercentageDone): """A generator that encapsulates your iterable, printing the percentage done. Usage:: p = ShowingPercentage(iterable, len(iterable), granularity=6) # Then use p instead of your iterable: for index, something in p: process(something) """ def __init__(self, iterable, max, **k): super(ShowingPercentage, self).__init__(max, **k) self.iterable = iterable def __iter__(self): for i, o in enumerate(self.iterable): yield i, o self.display(i)
[docs]def test_percentage(): """Demonstration of ShowingPercentage usage.""" from time import sleep for index, item in ShowingPercentage(range(100), max=100, granularity=4): sleep(.5)
[docs]def test_progress(): """Demonstration of ShowingProgress usage.""" from time import sleep for index, item in ShowingProgress(range(100), seconds=4): sleep(.237)