I'm trying to submit a PR for scikit-image, but I get a Travis-CI error:
Traceback (most recent call last):
File "doc/examples/edges/plot_canny.py", line 22, in <module>
from skimage import feature
File "/home/travis/build/scikit-image/scikit-image/skimage/feature/__init__.py", line 9, in <module>
from .peak import peak_local_max
File "/home/travis/build/scikit-image/scikit-image/skimage/feature/peak.py", line 3, in <module>
from ..filters import rank_order
File "/home/travis/build/scikit-image/scikit-image/skimage/filters/__init__.py", line 11, in <module>
from ._frangi import frangi_filter, hessian_filter
File "/home/travis/build/scikit-image/scikit-image/skimage/filters/_frangi.py", line 2, in <module>
from skimage.feature import hessian_matrix, hessian_matrix_eigvals
ImportError: cannot import name hessian_matrix
I suppose that this might be a circular import error, but I don't quite get how to resolve the issue. I've already included frangi_filter and hessian_filter into filter's module __init__.py.
I've also tried relative import, which resulted into the same errors.
How can I do a proper import, so the circular import issue can be resolved?