fix handling of prefixes with periods in them, fix #50

Author: derek73

docs/release_log.rst

@@ -2,6 +2,7 @@ Release Log
 ===========
 * 0.4.1 - July 25, 2016
     - Remove "bishop" from titles because it also could be a first name
+    - Fix handling of lastname prefixes with periods, e.g. "Jane St. John" (#50)
 * 0.4.0 - June 2, 2016
     - Remove "CONSTANTS.suffixes", replaced by "suffix_acronyms" and "suffix_not_acronyms" (#49)
     - Add "du" to prefixes

nameparser/parser.py

@@ -274,8 +274,8 @@ def is_conjunction(self, piece):
         return piece.lower() in self.C.conjunctions and not self.is_an_initial(piece)
 
     def is_prefix(self, piece):
-        """Is in the prefixes set and not :py:func:`is_an_initial()`."""
-        return piece.lower() in self.C.prefixes and not self.is_an_initial(piece)
+        """Lowercase and no periods version of piece is in the `~nameparser.config.titles.PREFIXES` set."""
+        return lc(piece) in self.C.prefixes
 
     def is_roman_numeral(self, value):
         """

tests.py

@@ -1378,6 +1378,11 @@ def test_prefix(self):
         self.m(hn.first, "Juan", hn)
         self.m(hn.last, "del Sur", hn)
 
+    def test_prefix_with_period(self):
+        hn = HumanName("Jill St. John")
+        self.m(hn.first, "Jill", hn)
+        self.m(hn.last, "St. John", hn)
+    
     def test_prefix_before_two_part_last_name(self):
         hn = HumanName("pennie von bergen wessels")
         self.m(hn.first, "pennie", hn)