Import pyDOE2 lazily for LatinHypercube

pySOT/experimental_design/lhd.py

@@ -1,7 +1,6 @@
 import warnings
 
 import numpy as np
-import pyDOE2 as pydoe
 
 from .experimental_design import ExperimentalDesign, _expdes_dist
 
@@ -52,6 +51,8 @@ def generate_points(self, lb=None, ub=None, int_var=None):
             int_var = np.array([])
 
         def wrapper():
+            import pyDOE2 as pydoe
+
             return pydoe.lhs(self.dim, self.num_pts, iterations=1)
 
         return _expdes_dist(wrapper, self.iterations, lb, ub, int_var)

tests/test_experimental_designs.py

@@ -1,3 +1,6 @@
+import subprocess
+import sys
+
 import numpy as np
 import pytest
 
@@ -39,6 +42,31 @@ def test_slhd():
         assert slhd.dim == 3
 
 
+def test_slhd_import_does_not_require_pydoe2():
+    script = """
+import importlib.abc
+import sys
+
+class BlockPyDOE2(importlib.abc.MetaPathFinder):
+    def find_spec(self, fullname, path=None, target=None):
+        if fullname == "pyDOE2":
+            raise ImportError("blocked pyDOE2 import")
+        return None
+
+sys.meta_path.insert(0, BlockPyDOE2())
+from pySOT.experimental_design import SymmetricLatinHypercube
+SymmetricLatinHypercube(dim=2, num_pts=4)
+"""
+    proc = subprocess.Popen(
+        [sys.executable, "-c", script],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+    )
+    _, stderr = proc.communicate()
+
+    assert proc.returncode == 0, stderr.decode("utf-8")
+
+
 def test_slhd_round():
     num_pts = 10
     dim = 3