napari.utils.cancelable_progress

class napari.utils.cancelable_progress(*_, **__)

Bases: progress

This class inherits from progress, providing the additional ability to cancel expensive executions. When progress is canceled by the user in the napari UI, two things will happen:

Firstly, the is_canceled attribute will become True, and the for loop will terminate after the current iteration, regardless of whether or not the iterator had more items.

Secondly, cancel_callback will be called, allowing the computation to close resources, repair state, etc.

See napari.utils.progress and tqdm.tqdm API for valid args and kwargs: https://tqdm.github.io/docs/tqdm/

Examples

>>> def long_running(steps=10, delay=0.1):
...     def on_cancel():
...         print("Canceled operation")
...     for i in cancelable_progress(range(steps), cancel_callback=on_cancel):
...         sleep(delay)

Methods

cancel()	Cancels the execution of the underlying computation.
clear([nolock])	Clear current bar display.
close()	Close progress object and emit event.
display([msg, pos])	Update the display and emit eta event.
external_write_mode([file, nolock])	Disable tqdm within context and refresh tqdm when exits.
format_interval(t)	Formats a number of seconds as a clock time, [H:]MM:SS
format_meter(n, total, elapsed[, ncols, ...])	Return a string-based progress bar given some parameters
format_num(n)	Intelligent scientific notation (.3g).
format_sizeof(num[, suffix, divisor])	Formats a number (greater than unity) with SI Order of Magnitude prefixes.
get_lock()	Get the global lock.
increment_with_overflow()	Update if not exceeding total, else set indeterminate range.
moveto(n)
pandas(**tqdm_kwargs)	Registers the current tqdm class with
refresh([nolock, lock_args])	Force refresh the display of this bar.
reset([total])	Resets to 0 iterations for repeated use.
set_description(desc)	Update progress description and emit description event.
set_description_str([desc, refresh])	Set/modify description without ': ' appended.
set_lock(lock)	Set the global lock.
set_postfix([ordered_dict, refresh])	Set/modify postfix (additional stats) with automatic formatting based on datatype.
set_postfix_str([s, refresh])	Postfix without dictionary expansion, similar to prefix handling.
status_printer(file)	Manage the printing and in-place updating of a line of characters.
unpause()	Restart tqdm timer from last print time.
update([n])	Update progress value by n and emit value event
wrapattr(stream, method[, total, bytes])	stream : file-like object. method : str, "read" or "write". The result of read() and the first argument of write() should have a len().
write(s[, file, end, nolock])	Print a message via tqdm (without overlap with bars).

Attributes

format_dict	Public API for read-only member access.
monitor
monitor_interval
total

Details

cancel()

Cancels the execution of the underlying computation. Note that the current iteration will be allowed to complete, however future iterations will not be run.