DOC: Updating the docstring of Series.str.extractall (pandas-dev#22565)

pandas/core/strings.py

@@ -957,19 +957,23 @@ def str_extractall(arr, pat, flags=0):
 
     Parameters
     ----------
-    pat : string
-        Regular expression pattern with capturing groups
+    pat : str
+        Regular expression pattern with capturing groups.
     flags : int, default 0 (no flags)
-        re module flags, e.g. re.IGNORECASE
+        A ``re`` module flag, for example ``re.IGNORECASE``. These allow
+        to modify regular expression matching for things like case, spaces,
+        etc. Multiple flags can be combined with the bitwise OR operator,
+        for example ``re.IGNORECASE | re.MULTILINE``.
 
     Returns
     -------
-    A DataFrame with one row for each match, and one column for each
-    group. Its rows have a MultiIndex with first levels that come from
-    the subject Series. The last level is named 'match' and indicates
-    the order in the subject. Any capture group names in regular
-    expression pat will be used for column names; otherwise capture
-    group numbers will be used.
+    DataFrame
+        A ``DataFrame`` with one row for each match, and one column for each
+        group. Its rows have a ``MultiIndex`` with first levels that come from
+        the subject ``Series``. The last level is named 'match' and indexes the
+        matches in each item of the ``Series``. Any capture group names in
+        regular expression pat will be used for column names; otherwise capture
+        group numbers will be used.
 
     See Also
     --------
@@ -1015,7 +1019,6 @@ def str_extractall(arr, pat, flags=0):
       1          a     2
     B 0          b     1
     C 0        NaN     1
-
     """
 
     regex = re.compile(pat, flags=flags)