sect: add Section.header

Author: ondrej-111

docx/section.py

@@ -96,6 +96,15 @@ def gutter(self):
     def gutter(self, value):
         self._sectPr.gutter = value
 
+    @lazyproperty
+    def header(self):
+        """|_Header| object representing default page header for this section.
+
+        The default header is used for odd-numbered pages when separate odd/even headers
+        are enabled. It is used for both odd and even-numbered pages otherwise.
+        """
+        return _Header(self._sectPr, self._document_part)
+
     @property
     def header_distance(self):
         """
@@ -207,3 +216,11 @@ class _Footer(BlockItemContainer):
     def __init__(self, sectPr, document_part):
         self._sectPr = sectPr
         self._document_part = document_part
+
+
+class _Header(BlockItemContainer):
+    """Page header."""
+
+    def __init__(self, sectPr, document_part):
+        self._sectPr = sectPr
+        self._document_part = document_part

features/sct-section.feature

@@ -9,7 +9,6 @@ Feature: Access and change section properties
      Then section.footer is a _Footer object
 
 
-  @wip
   Scenario: Section.header
     Given a Section object as section
      Then section.header is a _Header object

tests/test_section.py

@@ -8,7 +8,7 @@
 
 from docx.enum.section import WD_ORIENT, WD_SECTION
 from docx.parts.document import DocumentPart
-from docx.section import _Footer, Section, Sections
+from docx.section import _Footer, _Header, Section, Sections
 from docx.shared import Inches
 
 from .unitutil.cxml import element, xml
@@ -103,6 +103,18 @@ def it_provides_access_to_its_default_footer(
         _Footer_.assert_called_once_with(sectPr, document_part_)
         assert footer is footer_
 
+    def it_provides_access_to_its_default_header(
+        self, document_part_, _Header_, header_
+    ):
+        sectPr = element('w:sectPr')
+        _Header_.return_value = header_
+        section = Section(sectPr, document_part_)
+
+        header = section.header
+
+        _Header_.assert_called_once_with(sectPr, document_part_)
+        assert header is header_
+
     def it_knows_its_start_type(self, start_type_get_fixture):
         sectPr, expected_start_type = start_type_get_fixture
         section = Section(sectPr, None)
@@ -335,3 +347,11 @@ def _Footer_(self, request):
     @pytest.fixture
     def footer_(self, request):
         return instance_mock(request, _Footer)
+
+    @pytest.fixture
+    def _Header_(self, request):
+        return class_mock(request, "docx.section._Header")
+
+    @pytest.fixture
+    def header_(self, request):
+        return instance_mock(request, _Header)