ENH: Update isin docs with examples of ~ operator usage (#43959)

doc/source/user_guide/indexing.rst

@@ -997,6 +997,15 @@ a list of items you want to check for.
 
    df.isin(values)
 
+To return the DataFrame of booleans where the values are *not* in the original DataFrame,
+use the ``~`` operator:
+
+.. ipython:: python
+
+   values = {'ids': ['a', 'b'], 'vals': [1, 3]}
+
+   ~df.isin(values)
+
 Combine DataFrame's ``isin`` with the ``any()`` and ``all()`` methods to
 quickly select subsets of your data that meet a given criteria.
 To select a row where each column meets its own criterion:

pandas/core/frame.py

@@ -10559,6 +10559,13 @@ def isin(self, values) -> DataFrame:
         falcon      True       True
         dog        False       True
 
+        To check if ``values`` is *not* in the DataFrame, use the ``~`` operator:
+
+        >>> ~df.isin([0, 2])
+                num_legs  num_wings
+        falcon     False      False
+        dog         True      False
+
         When ``values`` is a dict, we can pass values to check for each
         column separately:
 

pandas/core/series.py

@@ -5012,6 +5012,17 @@ def isin(self, values) -> Series:
         5    False
         Name: animal, dtype: bool
 
+        To invert the boolean values, use the ``~`` operator:
+
+        >>> ~s.isin(['cow', 'lama'])
+        0    False
+        1    False
+        2    False
+        3     True
+        4    False
+        5     True
+        Name: animal, dtype: bool
+
         Passing a single string as ``s.isin('lama')`` will raise an error. Use
         a list of one element instead: