astype method now takes dict mapping col names to datatypes pandas-dev#14761

Updating documentation to reflect change

Author: m-charlton

doc/source/basics.rst

@@ -1755,12 +1755,14 @@ then the more *general* one will be used as the result of the operation.
    # conversion of dtypes
    df3.astype('float32').dtypes
 
+.. versionadded:: 0.20.0
+
 Convert a subset of columns to a specified type using :meth:`~DataFrame.astype`
 
 .. ipython:: python
 
    dft = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6], 'c': [7, 8, 9]})
-   dft[['a','b']] = dft[['a','b']].astype(np.uint8)
+   dft = dft.astype({'a': np.float64, 'c': np.uint8})
    dft
    dft.dtypes
 

doc/source/whatsnew/v0.20.0.txt

@@ -43,6 +43,16 @@ fixed-width text files, and :func:`read_excel` for parsing Excel files.
    pd.read_fwf(StringIO(data)).dtypes
    pd.read_fwf(StringIO(data), dtype={'a':'float64', 'b':'object'}).dtypes
 
+You can now pass a dictionary mapping column names to desired data types for that
+column to :meth:`~DataFrame.astype`.
+
+.. ipython:: python
+
+   dft = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6], 'c': [7, 8, 9]})
+   dft = dft.astype({'a': np.float64, 'c': np.uint8})
+   dft
+   dft.dtypes
+
 .. _whatsnew_0200.enhancements.other:
 
 Other enhancements