Add iswide() and width() method for UserString according as the

addition to unicode objects.

Lib/UserString.py

@@ -126,6 +126,10 @@ class UserString:
     def upper(self): return self.__class__(self.data.upper())
     def zfill(self, width): return self.__class__(self.data.zfill(width))
 
+    # the following methods are defined for unicode objects only:
+    def iswide(self): return self.data.iswide()
+    def width(self): return self.data.width()
+
 class MutableString(UserString):
     """mutable string objects
 

Lib/test/string_tests.py

@@ -695,3 +695,28 @@ class MixinStrUserStringTest:
 
         self.checkraises(TypeError, 'xyz', 'decode', 42)
         self.checkraises(TypeError, 'xyz', 'encode', 42)
+
+
+class MixinUnicodeUserStringTest:
+    # Additional tests that only work with
+    # unicode compatible object, i.e. unicode and UserString
+
+    def test_iswide(self):
+        self.checkequal(False, u'', 'iswide')
+        self.checkequal(False, u'\x1f', 'iswide') # Neutral
+        self.checkequal(False, u'\x20', 'iswide') # Narrow
+        self.checkequal(True, u'\u2329', 'iswide') # Wide
+        self.checkequal(False, u'\uff64', 'iswide') # Half
+        self.checkequal(True, u'\u3000', 'iswide') # Full
+        self.checkequal(False, u'\u2460', 'iswide') # Ambiguous
+        self.checkequal(True, u'\ud55c\uae00', 'iswide')
+        self.checkequal(False, u'\ud55c\u2606\uae00', 'iswide')
+
+    def test_width(self):
+        self.checkequal(0, u'', 'width')
+        self.checkequal(4, u'abcd', 'width')
+        self.checkequal(2, u'\u0187\u01c9', 'width')
+        self.checkequal(3, u'\u2460\u2329', 'width')
+        self.checkequal(3, u'\u2329\u2460', 'width')
+        self.checkequal(4, u'\ud55c\uae00', 'width')
+        self.checkequal(5, u'\ud55c\u2606\uae00', 'width')

Lib/test/test_userstring.py

@@ -11,7 +11,8 @@ class UserStringTest(
     string_tests.CommonTest,
     string_tests.MixinStrUnicodeUserStringTest,
     string_tests.MixinStrStringUserStringTest,
-    string_tests.MixinStrUserStringTest
+    string_tests.MixinStrUserStringTest,
+    string_tests.MixinUnicodeUserStringTest
     ):
 
     type2test = UserString