style: add Styles.__contains__()

Steve Canny · Steve Canny · commit 400b4e564d0d · 2015-02-08T00:01:39.000-08:00
diff --git a/docx/styles/styles.py b/docx/styles/styles.py
@@ -21,6 +21,16 @@ class Styles(ElementProxy):
 
     __slots__ = ()
 
+    def __contains__(self, name):
+        """
+        Enables `in` operator on style name.
+        """
+        name = self._translate_special_case_names(name)
+        for style in self._element.style_lst:
+            if style.name_val == name:
+                return True
+        return False
+
     def __getitem__(self, key):
         """
         Enables dictionary-style access by style id or UI name.
diff --git a/tests/styles/test_styles.py b/tests/styles/test_styles.py
@@ -20,6 +20,10 @@
 
 class DescribeStyles(object):
 
+    def it_supports_the_in_operator_on_style_name(self, in_fixture):
+        styles, name, expected_value = in_fixture
+        assert (name in styles) is expected_value
+
     def it_knows_its_length(self, len_fixture):
         styles, expected_value = len_fixture
         assert len(styles) == expected_value
@@ -250,6 +254,17 @@ def id_style_raises_fixture(self, style_):
         style_type = 2
         return styles, style_, style_type
 
+    @pytest.fixture(params=[
+        ('w:styles/w:style/w:name{w:val=heading 1}', 'Heading 1', True),
+        ('w:styles/w:style/w:name{w:val=Foo Bar}',   'Foo Bar',   True),
+        ('w:styles/w:style/w:name{w:val=heading 1}', 'Foobar',    False),
+        ('w:styles',                                 'Foobar',    False),
+    ])
+    def in_fixture(self, request):
+        styles_cxml, name, expected_value = request.param
+        styles = Styles(element(styles_cxml))
+        return styles, name, expected_value
+
     @pytest.fixture(params=[
         ('w:styles',                           0),
         ('w:styles/w:style',                   1),
