2 files changed, 40 insertions, 0 deletions
diff --git a/mammoth/docx/content_types_xml.py b/mammoth/docx/content_types_xml.py
new file mode 100644
index 0000000..a2da8e0
--- /dev/null
+++ b/mammoth/docx/content_types_xml.py
@@ -0,0 +1,21 @@
+def read_content_types_xml_element(element):
+    extension_defaults = dict(map(
+        _read_default,
+        element.find_children("content-types:Default"))
+    )
+    return ContentTypes(extension_defaults)
+
+
+def _read_default(element):
+    extension = element.attributes["Extension"]
+    content_type = element.attributes["ContentType"]
+    return extension, content_type
+
+
+class ContentTypes(object):
+    def __init__(self, extension_defaults):
+        self._extension_defaults = extension_defaults
+    
+    def find_content_type(self, path):
+        extension = path.rpartition(".")[2]
+        return self._extension_defaults.get(extension)
diff --git a/tests/docx/content_types_xml_tests.py b/tests/docx/content_types_xml_tests.py
new file mode 100644
index 0000000..56b5a86
--- /dev/null
+++ b/tests/docx/content_types_xml_tests.py
@@ -0,0 +1,19 @@
+from nose.tools import istest, assert_equal
+
+from mammoth.docx.xmlparser import element as xml_element
+from mammoth.docx.content_types_xml import read_content_types_xml_element
+
+
+@istest
+def content_type_is_based_on_default_for_extension_if_there_is_no_override():
+    element = xml_element("content-types:Types", {}, [
+        xml_element("content-types:Default", {
+            "Extension": "png",
+            "ContentType": "image/png",
+        })
+    ])
+    content_types = read_content_types_xml_element(element)
+    assert_equal(
+        "image/png",
+        content_types.find_content_type("word/media/hat.png"),
+    )