CLN: organize MultiIndex indexing tests (#31863)

* implement test_take

* move test_take, organize tests

* cleanup

* remove unused imports

* isort fixup

* typo fixup

Author: jbrockmendel

pandas/conftest.py

@@ -956,6 +956,25 @@ def __len__(self):
     return TestNonDictMapping
 
 
+def _gen_mi():
+    # a MultiIndex used to test the general functionality of this object
+
+    # See Also: tests.multi.conftest.idx
+    major_axis = Index(["foo", "bar", "baz", "qux"])
+    minor_axis = Index(["one", "two"])
+
+    major_codes = np.array([0, 0, 1, 2, 3, 3])
+    minor_codes = np.array([0, 1, 0, 1, 0, 1])
+    index_names = ["first", "second"]
+    mi = MultiIndex(
+        levels=[major_axis, minor_axis],
+        codes=[major_codes, minor_codes],
+        names=index_names,
+        verify_integrity=False,
+    )
+    return mi
+
+
 indices_dict = {
     "unicode": tm.makeUnicodeIndex(100),
     "string": tm.makeStringIndex(100),
@@ -972,6 +991,7 @@ def __len__(self):
     "interval": tm.makeIntervalIndex(100),
     "empty": Index([]),
     "tuples": MultiIndex.from_tuples(zip(["foo", "bar", "baz"], [1, 2, 3])),
+    "multi": _gen_mi(),
     "repeats": Index([0, 0, 1, 1, 2, 2]),
 }