DOC: Some cleaning up

Author: pfrcks

doc/source/basics.rst

@@ -1730,23 +1730,23 @@ Convert a subset of columns to a specified type using :meth:`~DataFrame.astype`
 
 .. ipython:: python
 
-   df = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6], 'c': [7, 8, 9]})
-   df[['a','b']] = df[['a','b']].astype(np.uint8)
-   df
-   df.dtypes
+   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.dtypes
 
 .. note::
 
     When trying to convert a subset of columns to a specified type using :meth:`~DataFrame.astype`  and :meth:`~DataFrame.loc`, utilizing **:** as mask, upcasting occurs.
 
-    :meth:`~DataFrame.loc` tries to fit in what we are assigning to the current dtypes, while [ ] will overwrite them taking the dtype from the right hand side. Therefore the following piece of code produces the unintended result.
+    :meth:`~DataFrame.loc` tries to fit in what we are assigning to the current dtypes, while ``[]`` will overwrite them taking the dtype from the right hand side. Therefore the following piece of code produces the unintended result.
 
 .. ipython:: python
 
-   df = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6], 'c': [7, 8, 9]})
-   df.loc[:, ['a', 'b']].astype(np.uint8).dtypes
-   df.loc[:, ['a', 'b']] = df.loc[:, ['a', 'b']].astype(np.uint8)
-   df.dtypes
+   dft = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6], 'c': [7, 8, 9]})
+   dft.loc[:, ['a', 'b']].astype(np.uint8).dtypes
+   dft.loc[:, ['a', 'b']] = dft.loc[:, ['a', 'b']].astype(np.uint8)
+   dft.dtypes
 
 object conversion
 ~~~~~~~~~~~~~~~~~