Update test_triangulation.py

Add black formatted code.

Author: philippeitis

adaptive/tests/unit/test_triangulation.py

@@ -63,14 +63,13 @@ def test_triangulation_find_opposing_vertices_raises_if_simplex_is_invalid():
 
 
 def test_circumsphere():
-    """ Test that circumsphere works correctly for a random center and random points on a sphere """
-    from adaptive.learner.triangulation import circumsphere, fast_norm
+    from adaptive.learner.triangulation import circumsphere
     from numpy import allclose
-    from numpy.random import normal, uniform
-    center_diff_err = "Calculated center (%s) differs from true center (%s)\n"
 
     def generate_random_sphere_points(dim, radius=0):
         """ Refer to https://math.stackexchange.com/a/1585996 """
+        from numpy.random import normal, uniform
+        from adaptive.learner.triangulation import fast_norm
 
         vec = [None] * (dim + 1)
         center = uniform(-100, 100, dim)
@@ -83,13 +82,20 @@ def generate_random_sphere_points(dim, radius=0):
 
         return radius, center, vec
 
+    center_diff_err = "Calculated center [%s] differs from true center [%s]\n"
     for dim in range(2, 10):
         radius, center, points = generate_random_sphere_points(dim)
         circ_center, circ_radius = circumsphere(points)
         err_msg = ""
         if not allclose(circ_center, center):
-            err_msg += center_diff_err % (", ".join([str(x) for x in circ_center]), ", ".join([str(x) for x in center]))
+            err_msg += center_diff_err % (
+                ",".join([str(x) for x in circ_center]),
+                ",".join([str(x) for x in center]),
+            )
         if not allclose(radius, circ_radius):
-            err_msg += "Calculated radius %s differs from true radius %s" % (circ_radius, radius)
+            err_msg += "Calculated radius %s differs from true radius %s" % (
+                circ_radius,
+                radius,
+            )
         if err_msg:
             raise AssertionError(err_msg)