[CI] Turn on pydocstyle and improve coverage

.github/workflows/lint-pydocstyle.yaml

@@ -12,8 +12,6 @@ on:
 
 jobs:
   pydocstyle:
-    # NOTE: Uncomment the following line to disable
-    if: false
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1

curvlinops/_base.py

@@ -179,8 +179,7 @@ def _check_deterministic(self):
 
     @staticmethod
     def print_nonclose(array1: ndarray, array2: ndarray, rtol: float, atol: float):
-        """Check if the two arrays are element-wise equal within a tolerance and print
-        the entries that differ.
+        """Check element-wise equality of two arrays and print differing entries.
 
         Args:
             array1: First array for comparison.

curvlinops/papyan2020traces/spectrum.py

@@ -79,6 +79,23 @@ def lanczos_approximate_spectrum_from_iter(
     kappa: float,
     margin: float,
 ) -> Tuple[ndarray, ndarray]:
+    """Estimate the spectral density from Lanczos iterations.
+
+    Args:
+        lanczos_iter: Eigenvalues and eigenvectors of the tri-diagonal matrix built up
+            during Lanczos iterations. ``evecs[:, i]`` is normalized eigenvector of
+            ``evals[i]``.
+        boundaries: Estimates of the minimum and maximum eigenvalues used as boundaries
+            for the spectral density's grid.
+        num_points: Resolution of the spectral density's grid.
+        kappa: Width of the Gaussian bumps used as approximate delta peaks in the
+            grid normalized to ``[-1; 1]``. Must be positive.
+        margin: Relative padding added around the boundary values (half to the left,
+            half to the right).
+
+    Returns:
+        The grid and the approximated spectral density.
+    """
     eval_min, eval_max = boundaries
     _width = eval_max - eval_min
     _padding = margin * _width

setup.cfg

@@ -118,4 +118,4 @@ strictness = full
 [pydocstyle]
 convention = google
 match = .*\.py
-match_dir = ^(?!(test|.git)).*
+match_dir = ^(?!(test|.git|docs)).*