Say 'delimiters', not 'combinations'

The maintenance branches do not deduce the dialect by trying
combinations of parameters, so only the delimiter candidates can tie.

Author: serhiy-storchaka

Doc/library/csv.rst

@@ -314,7 +314,7 @@ The :mod:`!csv` module defines the following classes:
       is given, it is interpreted as a string containing possible valid
       delimiter characters.
 
-      If several combinations fit the sample equally well ---
+      If several delimiters fit the sample equally well ---
       for example if both ``','`` and ``';'`` split every row consistently ---
       the delimiters ``','``, ``'\t'``, ``';'``, ``' '`` and ``':'``
       are preferred, in this order,

Lib/csv.py

@@ -244,7 +244,7 @@ def sniff(self, sample, delimiters=None):
         """
         Returns a dialect (or None) corresponding to the sample
 
-        If several combinations fit the sample equally well, the
+        If several delimiters fit the sample equally well, the
         delimiters listed in the preferred attribute are preferred, in
         that order, no matter how many times each of them occurs.
         """