* python/tag.cc: Support 'key in mapping' for TagSections

Support the replacement of mapping.has_key() for sections, and
update the usage in apt/package.py and apt/debfile accordingly.

This is implemented by extending the TagSecType with sequence
methods, but only settings the contains method there.

The TagSecGetAttr() function has been removed and replaced by
the use of the tp_methods slot.

1 files changed, 4 insertions, 0 deletions

diff --git a/doc/source/apt_pkg/cache.rst b/doc/source/apt_pkg/cache.rst
index af67d82f..146c2c2a 100644
--- a/doc/source/apt_pkg/cache.rst
+++ b/doc/source/apt_pkg/cache.rst
@@ -1199,6 +1199,10 @@ broken dependencies:
         Return the value of the field at *key*. If *key* is not available,
         raise :exc:`KeyError`.
 
+    .. describe:: key in section
+
+        Return ``True`` if *section* has a key *key*, else ``False``.
+
     .. method:: Bytes
 
         The number of bytes in the section.