hdr: add Section.header

Author: eupharis

docx/section.py

@@ -8,6 +8,9 @@
 
 from collections import Sequence
 
+from .header import Header
+from .shared import lazyproperty
+
 
 class Sections(Sequence):
     """
@@ -80,6 +83,16 @@ def gutter(self):
     def gutter(self, value):
         self._sectPr.gutter = value
 
+    @lazyproperty
+    def header(self):
+        """
+        Return the |Header| object representing the default header for this
+        section. A |Header| object is always returned, whether such a header
+        is present or not. The header itself is added, updated, or removed
+        using the returned object.
+        """
+        return Header(self._sectPr)
+
     @property
     def header_distance(self):
         """

features/sct-access-header.feature

@@ -3,7 +3,7 @@ Feature: Access section headers and footers
   As a developer using python-docx
   I need access to the section headers and footers
 
-  @wip
+
   Scenario: Access default header of section
     Given a section
      Then section.header is a Header object

tests/test_section.py

@@ -9,10 +9,12 @@
 import pytest
 
 from docx.enum.section import WD_ORIENT, WD_SECTION
+from docx.header import Header
 from docx.section import Section, Sections
 from docx.shared import Inches
 
 from .unitutil.cxml import element, xml
+from .unitutil.mock import class_mock, instance_mock
 
 
 class DescribeSections(object):
@@ -109,8 +111,20 @@ def it_can_change_its_page_margins(self, margins_set_fixture):
         setattr(section, margin_prop_name, new_value)
         assert section._sectPr.xml == expected_xml
 
+    def it_provides_access_to_its_header(self, header_fixture):
+        section, Header_, sectPr, header_ = header_fixture
+        header = section.header
+        Header_.assert_called_once_with(sectPr)
+        assert header is header_
+
     # fixtures -------------------------------------------------------
 
+    @pytest.fixture
+    def header_fixture(self, Header_, header_):
+        sectPr = element('w:sectPr')
+        section = Section(sectPr)
+        return section, Header_, sectPr, header_
+
     @pytest.fixture(params=[
         ('w:sectPr/w:pgMar{w:left=120}',   'left_margin',      76200),
         ('w:sectPr/w:pgMar{w:right=240}',  'right_margin',    152400),
@@ -247,3 +261,15 @@ def start_type_set_fixture(self, request):
         section = Section(element(initial_cxml))
         expected_xml = xml(expected_cxml)
         return section, new_start_type, expected_xml
+
+    # fixture components ---------------------------------------------
+
+    @pytest.fixture
+    def Header_(self, request, header_):
+        return class_mock(
+            request, 'docx.section.Header', return_value=header_
+        )
+
+    @pytest.fixture
+    def header_(self, request):
+        return instance_mock(request, Header)