cs.progress 20200716

A progress tracker with methods for throughput, ETA and update notification; also a compound progress meter composed from other progress meters.

A progress tracker with methods for throughput, ETA and update notification; also a compound progress meter composed from other progress meters.

Latest release 20200716:

• BaseProgress.status: distinguish "idle" (position >= total) from "stalled" (position < total).
• BaseProgress.status: make the status very short if the progress is idle.

Class BaseProgress

The base class for Progress and OverProcess with various common methods.

Note that durations are in seconds and that absolute time is in seconds since the UNIX epoch (the basis of time.time()).

Method BaseProgress.__init__(self, name=None, start_time=None, units_scale=None)

Initialise a progress instance.

Parameters:

• name: optional name
• start_time: optional UNIX epoch start time, default from time.time()
• units_scale: a scale for use with cs.units.transcribe, default BINARY_BYTES_SCALE

Class CheckPoint(builtins.tuple)

CheckPoint(time, position)

Class OverProgress(BaseProgress)

A Progress-like class computed from a set of subsidiary Progresses.

Example:

>>> P = OverProgress(name="over")
>>> P1 = Progress(name="progress1", position=12)
>>> P1.total = 100
>>> P1.advance(7)
>>> P2 = Progress(name="progress2", position=20)
>>> P2.total = 50
>>> P2.advance(9)
>>> P.add(P1)
>>> P.add(P2)
>>> P1.total
100
>>> P2.total
50
>>> P.total
150
>>> P1.start
12
>>> P2.start
20
>>> P.start
0
>>> P1.position
19
>>> P2.position
29
>>> P.position
16

Class Progress(BaseProgress)

A progress counter to track task completion with various utility methods.

Example:

>>> P = Progress(name="example")
>>> P                         #doctest: +ELLIPSIS
Progress(name='example',start=0,position=0,start_time=...,throughput_window=None,total=None):[CheckPoint(time=..., position=0)]
>>> P.advance(5)
>>> P                         #doctest: +ELLIPSIS
Progress(name='example',start=0,position=5,start_time=...,throughput_window=None,total=None):[CheckPoint(time=..., position=0), CheckPoint(time=..., position=5)]
>>> P.total = 100
>>> P                         #doctest: +ELLIPSIS
Progress(name='example',start=0,position=5,start_time=...,throughput_window=None,total=100):[CheckPoint(time=..., position=0), CheckPoint(time=..., position=5)]

A Progress instance has an attribute notify_update which is a set of callables. Whenever the position is updated, each of these will be called with the Progress instance and the latest CheckPoint.

Progress objects also make a small pretense of being an integer. The expression int(progress) returns the current position, and += and -= adjust the position.

This is convenient for coding, but importantly it is also useful for discretionary use of a Progress with some other object. If you want to make a lightweight Progress capable class you can set a position attribute to an int and manipulate it carefully using += and -= entirely. If you decide to incur the cost of maintaining a Progress object you can slot it in:

# initial setup with just an int
my_thing.amount = 0

# later, or on some option, use a Progress instance
my_thing.amount = Progress(my_thing.amount)

Method Progress.__init__(self, position=None, name=None, start=None, start_time=None, throughput_window=None, total=None, units_scale=None)

Initialise the Progesss object.

Parameters:

• position: initial position, default 0.
• name: optional name for this instance.
• start: starting position of progress range, default from position.
• start_time: start time of the process, default now.
• throughput_window: length of throughput time window in seconds, default None.
• total: expected completion value, default None.

Function progressbar(it, label=None, total=None, **kw)

Convenience function to construct and run a Progress.bar.

Parameters:

• it: the iterable to consume
• label: optional label, doubles as the Progress.name
• total: optional value for Progress.total, default from len(it) if supported.

If total is None and it supports len() then the Progress.total is set from it.

All arguments are passed through to Progress.bar.

Example use:

for row in progressbar(rows):
    ... do something with row ...

Release Log

Release 20200716:

• BaseProgress.status: distinguish "idle" (position >= total) from "stalled" (position < total).
• BaseProgress.status: make the status very short if the progress is idle.

Release 20200627:

• BaseProgress.status: handle throughput=None (before any activity).
• BaseProgress: drop count_of_total_bytes_text, superceded by format_counter (which honours the units_scale).

Release 20200626:

• New Progress.bar generator method iterating over an iterable while displaying a progress bar.
• New convenience function progressbar(it,...) which rolls its own Progress instance.
• Progress: always support a throughput window, default to DEFAULT_THROUGHPUT_WINDOW = 5s.
• Improve the default progress bar render returned by Progress.status().

Release 20200613:

• BaseProgress, Progress and OverProgress now accept an optional units_scale, such as cs.units.UNSCALED_SCALE, to use when expressing progress - the default remains BINARY_SCALE.
• New arrow(), format_counter() and text_pos_of_total() methods to produce components of the status string for tuning or external reuse.

Release 20200520: OverProgress: throughput and eta implementations.

Release 20200129.3: Test version machinery again.

Release 20200129.2: set version to '20200129.2'

Release 20200129.1: Dummy release to test new version.

Release 20200129: New Progress.count_of_total_bytes_text property presenting "3kB/40MB" style text.

Release 20190812:

• New OverProgress class which is a composite of a set of subsidiary Progress instances.
• Assorted other small updates.

Release 20190220:

• Progress: be somewhat like an int.
• New status() method returning a convenient one line progress status report.

Release 20180703.2: Progress: make .total into a property in order to fire the update notifications.

Release 20180703.1: Progress: additions and changes to API: new .ratio, .elapsed_time, rename .projected to .remaining_time.

Release 20180703: Initial release of cs.progress.