Add parent property

zipp.py

@@ -140,13 +140,15 @@ def __str__(self):
     def __repr__(self):
         return self.__repr.format(self=self)
 
-    def __truediv__(self, add):
+    def joinpath(self, add):
         add = self._pathlib_compat(add)
         next = posixpath.join(self.at, add)
         next_dir = posixpath.join(self.at, add, "")
         names = self._names()
         return self._next(next_dir if next not in names and next_dir in names else next)
 
+    __truediv__ = joinpath
+
     @staticmethod
     def _add_implied_dirs(names):
         return names + [
@@ -155,6 +157,13 @@ def _add_implied_dirs(names):
             if name and name + "/" not in names
         ]
 
+    @property
+    def parent(self):
+        parent_at = posixpath.dirname(self.at)
+        if parent_at:
+            parent_at += '/'
+        return self._next(parent_at)
+
     def _names(self):
         return self._add_implied_dirs(self.root.namelist())