[Documentation] Added another example in df.clip documentation. (pandas-dev#55589)

* Update generic.py

* Update generic.py

* Update generic.py

Fix for issue pandas-dev#55509 (updating intersection only)

fix typo - black

Added test

Author: abhi-glitchhg

pandas/core/frame.py

@@ -8857,11 +8857,11 @@ def update(
         if not isinstance(other, DataFrame):
             other = DataFrame(other)
 
-        other = other.reindex(self.index)
+        indexes_intersection = self.index.intersection(other.index)
 
         for col in self.columns.intersection(other.columns):
-            this = self[col]._values
-            that = other[col]._values
+            this = self[col].loc[indexes_intersection]._values
+            that = other[col].loc[indexes_intersection]._values
 
             if filter_func is not None:
                 mask = ~filter_func(this) | isna(that)
@@ -8881,7 +8881,7 @@ def update(
             if mask.all():
                 continue
 
-            self.loc[:, col] = expressions.where(mask, this, that)
+            self.loc[indexes_intersection, col] = expressions.where(mask, this, that)
 
     # ----------------------------------------------------------------------
     # Data reshaping

pandas/core/generic.py

@@ -8785,6 +8785,16 @@ def clip(
         3     -1      6
         4      5     -4
 
+        Clips using specific lower and upper thresholds per column:
+
+        >>> df.clip([-2, -1], [4,5])
+            col_0  col_1
+        0      4     -1
+        1     -2     -1
+        2      0      5
+        3     -1      5
+        4      4     -1
+
         Clips using specific lower and upper thresholds per column element:
 
         >>> t = pd.Series([2, -4, -1, 6, 3])

pandas/tests/frame/methods/test_update.py

@@ -177,3 +177,12 @@ def test_update_dt_column_with_NaT_create_column(self):
             {"A": [1.0, 3.0], "B": [pd.NaT, pd.to_datetime("2016-01-01")]}
         )
         tm.assert_frame_equal(df, expected)
+
+    def test_update_preserve_column_dtype_bool(self):
+        # GH#55509
+        df = DataFrame({"A": [True, True]}, index=[1, 2])
+        other = DataFrame({"A": [False]}, index=[1])
+        expected = DataFrame({"A": [False, True]}, index=[1, 2])
+        df.update(other)
+
+        tm.assert_frame_equal(df, expected)