ci: forbid module-level import of scipy & matplotlib

Author: yaugenst-flex

pyproject.toml

@@ -277,6 +277,9 @@ extend-ignore = [
 [tool.ruff.lint.isort]
 required-imports = ["from __future__ import annotations"]
 
+[tool.ruff.lint.flake8-tidy-imports]
+banned-module-level-imports = ["scipy", "matplotlib"]
+
 [tool.ruff.lint.per-file-ignores]
 "tests/**/*" = [
     "B015",   # useless comparison
@@ -287,6 +290,10 @@ required-imports = ["from __future__ import annotations"]
     "S101",   # asserts allowed in tests
     "NPY201", # numpy 2.* compatibility check
     "TID252", # allow relative imports in tests
+    "TID253", # allow heavy imports in tests
+]
+"tidy3d/plugins/**/*" = [
+    "TID253", # allow heavy imports in plugins (not used by MC)
 ]
 
 [tool.pytest.ini_options]

tidy3d/components/mode/mode_solver.py

@@ -11,8 +11,6 @@
 import numpy as np
 import pydantic.v1 as pydantic
 import xarray as xr
-from matplotlib.collections import PatchCollection
-from matplotlib.patches import Rectangle
 
 from tidy3d.components.base import Tidy3dBaseModel, cached_property, skip_if_fields_missing
 from tidy3d.components.boundary import PML, Absorber, Boundary, BoundarySpec, PECBoundary, StablePML
@@ -2394,6 +2392,10 @@ def _plot_pml(
         cls, simulation: Simulation, plane: Box, mode_spec: ModeSpec, ax: Ax = None
     ) -> Ax:
         """Plot the mode plane absorbing boundaries."""
+
+        from matplotlib.collections import PatchCollection
+        from matplotlib.patches import Rectangle
+
         # Get the mode plane normal axis, center, and limits.
         _, h_lim, v_lim, _ = cls._center_and_lims(simulation=simulation, plane=plane)
 

tidy3d/components/viz/axes_utils.py

@@ -3,16 +3,15 @@
 from functools import wraps
 from typing import Optional
 
-import matplotlib.pyplot as plt
-import matplotlib.ticker as ticker
-
 from tidy3d.components.types import Ax, Axis, LengthUnit
 from tidy3d.constants import UnitScaling
 from tidy3d.exceptions import Tidy3dKeyError
 
 
 def make_ax() -> Ax:
     """makes an empty ``ax``."""
+    import matplotlib.pyplot as plt
+
     _, ax = plt.subplots(1, 1, tight_layout=True)
     return ax
 
@@ -60,6 +59,9 @@ def set_default_labels_and_title(
     When the ``plot_length_units`` are specified, the plot axes are scaled, and
     the title and axis labels include the desired units.
     """
+
+    import matplotlib.ticker as ticker
+
     xlabel = axis_labels[0]
     ylabel = axis_labels[1]
     if plot_length_units is not None: