tests: Format all Python code with black, except tests in basics subdir.

This adds the Python files in the tests/ directory to be formatted with
./tools/codeformat.py.  The basics/ subdirectory is excluded for now so we
aren't changing too much at once.

In a few places `# fmt: off`/`# fmt: on` was used where the code had
special formatting for readability or where the test was actually testing
the specific formatting.

tests/float/math_isclose.py

@@ -6,19 +6,22 @@ except ImportError:
     print("SKIP")
     raise SystemExit
 
+
 def test(a, b, **kwargs):
     print(isclose(a, b, **kwargs))
 
+
 def test_combinations(a, b, **kwargs):
     test(a, a, **kwargs)
     test(a, b, **kwargs)
     test(b, a, **kwargs)
     test(b, b, **kwargs)
 
+
 # Special numbers
-test_combinations(float('nan'), 1)
-test_combinations(float('inf'), 1)
-test_combinations(float('-inf'), 1)
+test_combinations(float("nan"), 1)
+test_combinations(float("inf"), 1)
+test_combinations(float("-inf"), 1)
 
 # Equality
 test(1.0, 1.0, rel_tol=0.0, abs_tol=0.0)
@@ -40,8 +43,8 @@ test(0.0, 1e-10, abs_tol=0.0, rel_tol=0.1)
 try:
     isclose(0, 0, abs_tol=-1)
 except ValueError:
-    print('ValueError')
+    print("ValueError")
 try:
     isclose(0, 0, rel_tol=-1)
 except ValueError:
-    print('ValueError')
+    print("ValueError")