DOC/TST: Clarify Series.str.get supports passing hashable label

doc/source/whatsnew/v1.5.0.rst

@@ -279,6 +279,7 @@ Other enhancements
 - :class:`Series` reducers (e.g. ``min``, ``max``, ``sum``, ``mean``) will now successfully operate when the dtype is numeric and ``numeric_only=True`` is provided; previously this would raise a ``NotImplementedError`` (:issue:`47500`)
 - :meth:`RangeIndex.union` now can return a :class:`RangeIndex` instead of a :class:`Int64Index` if the resulting values are equally spaced (:issue:`47557`, :issue:`43885`)
 - :meth:`DataFrame.compare` now accepts an argument ``result_names`` to allow the user to specify the result's names of both left and right DataFrame which are being compared. This is by default ``'self'`` and ``'other'`` (:issue:`44354`)
+- :meth:`Series.str.get` now raises when ``i`` is not a integer (:issue:`47911`)
 
 .. ---------------------------------------------------------------------------
 .. _whatsnew_150.notable_bug_fixes:

pandas/core/strings/accessor.py

@@ -1045,6 +1045,9 @@ def get(self, i):
         5    None
         dtype: object
         """
+        if not is_integer(i):
+            msg = f"i must be of integer type, not {type(i).__name__}"
+            raise TypeError(msg)
         result = self._data.array._str_get(i)
         return self._wrap_result(result)
 

pandas/tests/strings/test_strings.py

@@ -828,3 +828,21 @@ def test_zfill_with_leading_sign():
     value = Series(["-cat", "-1", "+dog"])
     expected = Series(["-0cat", "-0001", "+0dog"])
     tm.assert_series_equal(value.str.zfill(5), expected)
+
+
+@pytest.mark.parametrize("arg", [{1: 1}, [1, 2], (1, 2), "0"])
+def test_get_with_non_integer_argument(arg):
+    # GH47911
+    s = Series(
+        [
+            "String",
+            (1, 2, 3),
+            ["a", "b", "c"],
+            123,
+            -456,
+            {1: "Hello", "2": "World"}
+        ]
+    )
+    msg = f"i must be of integer type, not {type(arg).__name__}"
+    with pytest.raises(TypeError, match=msg):
+        s.str.get(arg)