napari.utils#

Classes

Colormap

Colormap that relates intensity values to colors.

DirectLabelColormap

Colormap using a direct mapping from labels to color using a dict.

CyclicLabelColormap

Color cycle with a background value.

cancelable_progress

This class inherits from progress, providing the additional ability to cancel expensive executions.

nbscreenshot

alias of NotebookScreenshot

NotebookScreenshot

Display napari screenshot in the jupyter notebook.

progress

This class inherits from tqdm and provides an interface for progress bars in the napari viewer.

Functions

napari.utils.progrange(*args, **kwargs)[source]#

Shorthand for progress(range(*args), **kwargs).

Adds tqdm based progress bar to napari viewer, if it exists, and returns the wrapped range object.

Returns:

wrapped range object

Return type:

progress

napari.utils.resize_dask_cache(nbytes: int | None = None, mem_fraction: float | None = None) → Cache[source]#

Create or resize the dask cache used for opportunistic caching.

The cache object is an instance of a Cache, (which wraps a cachey.Cache).

See Dask opportunistic caching

Parameters:

  • nbytes (int, optional) – The desired size of the cache, in bytes. If None, the cache size will autodetermined as fraction of the total memory in the system, using mem_fraction. If nbytes is 0. The cache is turned off. by default, cache size is autodetermined using mem_fraction.

  • mem_fraction (float, optional) – The fraction (from 0 to 1) of total memory to use for the dask cache.

Returns:

dask_cache – An instance of a Dask Cache

Return type:

dask.cache.Cache

Examples

>>> from napari.utils import resize_dask_cache
>>> cache = resize_dask_cache()  # use 25% of total memory by default

>>> # dask.Cache wraps cachey.Cache
>>> assert isinstance(cache.cache, cachey.Cache)

>>> # useful attributes
>>> cache.cache.available_bytes  # full size of cache
>>> cache.cache.total_bytes   # currently used bytes
napari.utils.sys_info(as_html: bool = False) → str[source]#

Gathers relevant module versions for troubleshooting purposes.

Parameters:

as_html (bool) – if True, info will be returned as HTML, suitable for a QTextEdit widget