fixes test name and style in whatsnew

Author: datajanko

doc/source/whatsnew/v0.23.0.txt

@@ -181,21 +181,15 @@ Please note that the string `index` is not supported with the round trip format,
 ``.assign()`` accepts dependent arguments
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-The :func:`DataFrame.assign()` now accepts dependent kwargs. (:issue: `14207)
+The :func:`DataFrame.assign()` now accepts dependent kwargs. (:issue:`14207`)
 
 Specifically, defining a new column inside ``.assign()`` may be referenced in the same assign statement if a callable is used. For example
 
-.. ipython:: python     
+.. 	ipython:: python     
 
     In [3]: df = pd.DataFrame({'A': [1, 2, 3]})
 
     In [4]: df.assign(B=df.A, C=lambda x:x['A']+ x['B'])
-    Out[4]:
-       A  B  C
-    0  1  1  2
-    1  2  2  4
-    2  3  3  6
-
 .. warning::
 
 This may subtly change the behavior of your code when you're
@@ -219,15 +213,7 @@ New Behaviour:
 
 .. ipython:: python
 
-  
-    In [4]: df = pd.DataFrame({"A": [1, 2, 3]})
-
     In [5]: df.assign(A=df.A+1, C= lambda df: df.A* -1)
-    Out[5]:
-       A  C
-    0  2 -2
-    1  3 -3
-    2  4 -4
 
 .. _whatsnew_0230.enhancements.other:
 

pandas/tests/frame/test_mutate_columns.py

@@ -92,7 +92,7 @@ def test_assign_bad(self):
 
     @pytest.mark.skipif(PY36, reason="""Issue #14207: valid for python
                         3.6 and above""")
-    def test_assign_bad_old_version(self):
+    def test_assign_dependent_old_python(self):
         df = DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]})
 
         # Key C does not exist at defition time of df