Mark test relying on optional dependencies as skip

test/test_individual.py

@@ -1,7 +1,19 @@
 import math
 import pickle
 import pytest
-import torch
+
+try:
+    import sympy  # noqa: F401
+
+    sympy_available = True
+except ModuleNotFoundError:
+    sympy_available = False
+try:
+    import torch  # noqa: F401
+
+    torch_available = True
+except ModuleNotFoundError:
+    torch_available = False
 
 import gp
 from gp.individual import Individual
@@ -56,6 +68,7 @@ def test_individual_with_parameter_python():
     assert y[0] == pytest.approx(x[0] + c)
 
 
+@pytest.mark.skipif(not torch_available, reason="torch is not installed.")
 def test_individual_with_parameter_torch():
 
     primitives = (gp.Add, gp.Parameter)
@@ -96,6 +109,7 @@ def test_individual_with_parameter_torch():
     assert y[1, 0].item() == pytest.approx(x[1, 0].item() + c)
 
 
+@pytest.mark.skipif(not sympy_available, reason="sympy is not installed.")
 def test_individual_with_parameter_sympy():
 
     primitives = (gp.Add, gp.Parameter)
@@ -134,6 +148,7 @@ def test_individual_with_parameter_sympy():
     assert y == pytest.approx(x[0] + c)
 
 
+@pytest.mark.skipif(not torch_available, reason="torch is not installed.")
 def test_to_and_from_torch_plus_backprop():
     primitives = (gp.Mul, gp.Parameter)
     genome = gp.Genome(1, 1, 2, 2, 1, primitives)