improve docs

Author: mroeschke

doc/source/user_guide/io.rst

@@ -1295,57 +1295,41 @@ too many fields will raise an error by default:
 
 You can elect to skip bad lines:
 
-.. code-block:: ipython
-
-    In [29]: pd.read_csv(StringIO(data), on_bad_lines="warn")
-    Skipping line 3: expected 3 fields, saw 4
+.. ipython:: ipython
 
-    Out[29]:
-       a  b   c
-    0  1  2   3
-    1  8  9  10
+    pd.read_csv(StringIO(data), on_bad_lines="warn")
 
 Or pass a callable function to handle the bad line if ``engine="python"``.
 The bad line will be a list of strings that was split by the ``sep``:
 
-.. code-block:: ipython
+.. versionadded:: 1.4.0
+
+.. ipython:: ipython
+
+    external_list = []
 
-    In [30]: pd.read_csv(StringIO(data), on_bad_lines=lambda x: x[-3:], engine="python")
-    Out[30]:
-       a  b   c
-    0  1  2   3
-    1  5  6   7
-    2  8  9  10
+    def func(line):
+        external_list.append(line)
+        return line[-3:]
 
-    .. versionadded:: 1.4.0
+    pd.read_csv(StringIO(data), on_bad_lines=func, engine="python")
 
+    external_list
 
 You can also use the ``usecols`` parameter to eliminate extraneous column
 data that appear in some lines but not others:
 
-.. code-block:: ipython
-
-   In [31]: pd.read_csv(StringIO(data), usecols=[0, 1, 2])
+.. ipython:: ipython
 
-    Out[31]:
-       a  b   c
-    0  1  2   3
-    1  4  5   6
-    2  8  9  10
+   pd.read_csv(StringIO(data), usecols=[0, 1, 2])
 
 In case you want to keep all data including the lines with too many fields, you can
 specify a sufficient number of ``names``. This ensures that lines with not enough
 fields are filled with ``NaN``.
 
-.. code-block:: ipython
-
-   In [32]: pd.read_csv(StringIO(data), names=['a', 'b', 'c', 'd'])
+.. ipython:: ipython
 
-   Out[32]:
-       a  b   c  d
-    0  1  2   3  NaN
-    1  4  5   6  7
-    2  8  9  10  NaN
+   pd.read_csv(StringIO(data), names=['a', 'b', 'c', 'd'])
 
 .. _io.dialect: