Resolve merge conflict in whatsnew/v3.0.0.rst

Author: cmjcharlton

asv_bench/benchmarks/frame_methods.py

@@ -862,4 +862,28 @@ def time_last_valid_index(self, dtype):
         self.df.last_valid_index()
 
 
+class Update:
+    def setup(self):
+        rng = np.random.default_rng()
+        self.df = DataFrame(rng.uniform(size=(1_000_000, 10)))
+
+        idx = rng.choice(range(1_000_000), size=1_000_000, replace=False)
+        self.df_random = DataFrame(self.df, index=idx)
+
+        idx = rng.choice(range(1_000_000), size=100_000, replace=False)
+        cols = rng.choice(range(10), size=2, replace=False)
+        self.df_sample = DataFrame(
+            rng.uniform(size=(100_000, 2)), index=idx, columns=cols
+        )
+
+    def time_to_update_big_frame_small_arg(self):
+        self.df.update(self.df_sample)
+
+    def time_to_update_random_indices(self):
+        self.df_random.update(self.df_sample)
+
+    def time_to_update_small_frame_big_arg(self):
+        self.df_sample.update(self.df)
+
+
 from .pandas_vb_common import setup  # noqa: F401 isort:skip

ci/code_checks.sh

@@ -153,11 +153,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         -i "pandas.DatetimeTZDtype SA01" \
         -i "pandas.DatetimeTZDtype.tz SA01" \
         -i "pandas.DatetimeTZDtype.unit SA01" \
-        -i "pandas.ExcelFile PR01,SA01" \
-        -i "pandas.ExcelFile.parse PR01,SA01" \
-        -i "pandas.ExcelWriter SA01" \
-        -i "pandas.Float32Dtype SA01" \
-        -i "pandas.Float64Dtype SA01" \
         -i "pandas.Grouper PR02,SA01" \
         -i "pandas.HDFStore.append PR01,SA01" \
         -i "pandas.HDFStore.get SA01" \

doc/source/getting_started/install.rst

@@ -269,6 +269,8 @@ SciPy                     1.10.0             computation     Miscellaneous stati
 xarray                    2022.12.0          computation     pandas-like API for N-dimensional data
 ========================= ================== =============== =============================================================
 
+.. _install.excel_dependencies:
+
 Excel files
 ^^^^^^^^^^^
 

doc/source/getting_started/intro_tutorials/02_read_write.rst

@@ -111,6 +111,12 @@ strings (``object``).
 
 My colleague requested the Titanic data as a spreadsheet.
 
+.. note::
+    If you want to use :func:`~pandas.to_excel` and :func:`~pandas.read_excel`,
+    you need to install an Excel reader as outlined in the
+    :ref:`Excel files <install.excel_dependencies>` section of the
+    installation documentation.
+
 .. ipython:: python
 
     titanic.to_excel("titanic.xlsx", sheet_name="passengers", index=False)

doc/source/user_guide/missing_data.rst

@@ -386,6 +386,27 @@ Replace NA with a scalar value
    df
    df.fillna(0)
 
+When the data has object dtype, you can control what type of NA values are present.
+
+.. ipython:: python
+
+   df = pd.DataFrame({"a": [pd.NA, np.nan, None]}, dtype=object)
+   df
+   df.fillna(None)
+   df.fillna(np.nan)
+   df.fillna(pd.NA)
+
+However when the dtype is not object, these will all be replaced with the proper NA value for the dtype.
+
+.. ipython:: python
+
+   data = {"np": [1.0, np.nan, np.nan, 2], "arrow": pd.array([1.0, pd.NA, pd.NA, 2], dtype="float64[pyarrow]")}
+   df = pd.DataFrame(data)
+   df
+   df.fillna(None)
+   df.fillna(np.nan)
+   df.fillna(pd.NA)
+
 Fill gaps forward or backward
 
 .. ipython:: python