Guidelines#

  • All code should have tests (see test coverage for more details).

  • All code should be documented, to the same standard as NumPy and SciPy.

  • For new functionality, always add an example to the gallery (see Gallery for more details).

  • No changes are ever merged without review and approval by two core team members. There are two exceptions to this rule. First, pull requests which affect only the documentation require review and approval by only one core team member in most cases. If the maintainer feels the changes are large or likely to be controversial, two reviews should still be encouraged. The second case is that of minor fixes which restore CI to a working state, because these should be merged fairly quickly. Reach out on the developer forum if you get no response to your pull request. Never merge your own pull request.

Stylistic Guidelines#

  • Use the following import conventions:

    import numpy as np
import matplotlib.pyplot as plt
import scipy as sp
import skimage as ski

sp.ndimage.label(...)
ski.measure.label(...)

  • Use numpy data types instead of strings (np.uint8 instead of "uint8").

  • When documenting array parameters, use image : ndarray of shape (M, N) and then refer to M and N in the docstring, if necessary.

  • Refer to array dimensions as (plane), row, column, not as x, y, z. See Coordinate conventions in the user guide for more information.

  • Functions should support all input image dtypes. Use utility functions such as img_as_float to help convert to an appropriate type. The output format can be whatever is most efficient. This allows us to string together several functions into a pipeline, e.g.:

    hough(canny(my_image))

  • Use relative module imports, i.e. from .._shared import xyz rather than from _skimage2._shared import xyz.

  • For Cython functions:

    • Release the GIL whenever possible, using with nogil:.

    • Wrap Cython code in a pure Python function, which defines the API. This improves compatibility with code introspection tools, which are often not aware of Cython code.

  • Use Py_ssize_t as data type for all indexing, shape and size variables in C/C++ and Cython code.