more methods and operators for the Jeep class

git-svn-id: svn://svn.cy55.de/Zope3/src/cybertools/trunk@1609 fd906abe-77d9-0310-91a1-e0d9ade77398

util/jeep.py

@@ -30,11 +30,14 @@ class Jeep(object):
 
     _attributes = ('_sequence',)
 
-    def __init__(self, init=None):
+    def __init__(self, seq=[]):
         self._sequence = []
-        if init is not None:
-            for attr, value in init:
-                setattr(self, attr, value)
+        for item in seq:
+            attr, value = item
+            setattr(self, attr, value)
+
+    def __len__(self):
+        return len(self._sequence)
 
     def __iter__(self):
         for key in self._sequence:
@@ -46,8 +49,12 @@ class Jeep(object):
                 self._sequence.append(attr)
         object.__setattr__(self, attr, value)
 
+    def __delattr__(self, attr):
+        del self._sequence[self.index(attr)]
+        object.__delattr__(self, attr)
+
     def __getitem__(self, key):
-        if type(key) is int:
+        if type(key) in (int, long):
             return getattr(self, self._sequence[key])
         value = getattr(self, key, _notfound)
         if value is _notfound:
@@ -57,6 +64,12 @@ class Jeep(object):
     def __setitem__(self, key, value):
         setattr(self, key, value)
 
+    def __delitem__(self, key):
+        delattr(self, key)
+
+    def __contains__(self, key):
+        return getattr(self, key, _notfound) is not _notfound
+
     def keys(self):
         return list(self)
 
@@ -68,3 +81,31 @@ class Jeep(object):
 
     def get(self, key, default=None):
         return getattr(self, key, default)
+
+    def index(self, key):
+        return self._sequence.index(key)
+
+    def append(self, obj):
+        key = getattr(obj, '__name__', _notfound)
+        if key is _notfound:
+            raise AttributeError("No '__name__' attribute present")
+        if key in self:
+            raise ValueError("Object already present")
+        self[key] = obj
+
+    def insert(self, idx, obj):
+        key = getattr(obj, '__name__', _notfound)
+        if key is _notfound:
+            raise AttributeError("No '__name__' attribute present")
+        if key in self:
+            raise ValueError("Object already present")
+        self._sequence.insert(idx, key)
+        object.__setattr__(self, key, obj)
+
+    def pop(self, key=-1):
+        value = self[key]
+        if type(key) in (int, long):
+            key = self._sequence[key]
+        delattr(self, key)
+        return value
+

util/jeep.txt

@@ -65,13 +65,10 @@ More Dictionary Methods
 
   >>> jeep.get('second')
   'new second value'
-
   >>> jeep.get('fourth', 'default')
   'default'
-
   >>> jeep.get('fourth') is None
   True
-
   >>> jeep['fourth']
   Traceback (most recent call last):
   ...
@@ -80,6 +77,60 @@ More Dictionary Methods
   >>> dict(jeep)
   {'second': 'new second value', 'third': 'third value', 'first': 'first value'}
 
+More Methods and Operators
+--------------------------
+
+  >>> 'third' in jeep
+  True
+
+  >>> jeep.pop()
+  'third value'
+  >>> len(jeep)
+  2
+
+  >>> 'third' in jeep
+  False
+
+  >>> jeep.index('second')
+  1
+  >>> jeep.index('third')
+  Traceback (most recent call last):
+  ...
+  ValueError: ...not in list
+
+Sequence Additions with Named Objects
+-------------------------------------
+
+Objects that have a ``__name__`` attribute can be appended
+to a Jeep object as the dictionary key can be obtained from these attribute.
+
+  >>> class Term(object):
+  ...     def __init__(self, token, title=None, value=None):
+  ...         self.__name__ = self.token = token
+  ...         self.title = title or token
+  ...         self.value = value or title or token
+
+  >>> t1 = Term('term1', 'title 1')
+  >>> jeep.append(t1)
+  >>> list(jeep)
+  ['first', 'second', 'term1']
+  >>> jeep.term1.title
+  'title 1'
+
+  >>> jeep.insert(1, Term('term2', 'title 2'))
+  >>> list(jeep)
+  ['first', 'term2', 'second', 'term1']
+  >>> jeep[1].title
+  'title 2'
+
+Inserting or appending an object with a name that's already present raises
+an exception:
+
+  >>> jeep.append(t1)
+  Traceback (most recent call last):
+  ...
+  ValueError: ...already present
+
 Constructors
 ------------