genshi.core.Attrs

Package genshi :: Module core :: Class Attrs |

# Class Attrs

    object --+
             |
         tuple --+
                 |
                Attrs

Immutable sequence type that stores the attributes of an element.

Ordering of the attributes is preserved, while access by name is also supported.

    >>> attrs = Attrs([('href', '#'), ('title', 'Foo')])
    >>> attrs
    Attrs([('href', '#'), ('title', 'Foo')])

    >>> 'href' in attrs
    True
    >>> 'tabindex' in attrs
    False
    >>> attrs.get('title')
    'Foo'

Instances may not be manipulated directly. Instead, the operators `|` and `-` can be used to produce new instances that have specific attributes added, replaced or removed.

To remove an attribute, use the `-` operator. The right hand side can be either a string or a set/sequence of strings, identifying the name(s) of the attribute(s) to remove:

    >>> attrs - 'title'
    Attrs([('href', '#')])
    >>> attrs - ('title', 'href')
    Attrs()

The original instance is not modified, but the operator can of course be used with an assignment:

    >>> attrs
    Attrs([('href', '#'), ('title', 'Foo')])
    >>> attrs -= 'title'
    >>> attrs
    Attrs([('href', '#')])

To add a new attribute, use the `|` operator, where the right hand value is a sequence of `(name, value)` tuples (which includes Attrs instances):

    >>> attrs | [('title', 'Bar')]
    Attrs([('href', '#'), ('title', 'Bar')])

If the attributes already contain an attribute with a given name, the value of that attribute is replaced:

    >>> attrs | [('href', 'http://example.org/')]
    Attrs([('href', 'http://example.org/')])

Instance Methods
`bool` |
__contains__(self, name) Return whether the list includes an attribute with the specified name. |
__getitem__(self, i) Return an item or slice of the attributes list. |
__getslice__(self, i, j) Return a slice of the attributes list. |
Attrs |
__or__(self, attrs) Return a new instance that contains the attributes in `attrs` in addition to any already existing attributes. Any attributes in the new set that have a value of `None` are removed. |
__repr__(self) repr(x) |
Attrs |
__sub__(self, names) Return a new instance with all attributes with a name in `names` are removed. |
`object` |
get(self, name, default=None) Return the value of the attribute with the specified name, or the value of the `default` parameter if no such attribute is found. |
`tuple` |
totuple(self) Return the attributes as a markup event. |
Inherited from `tuple`: `__add__`, `__eq__`, `__ge__`, `__getattribute__`, `__getnewargs__`, `__gt__`, `__hash__`, `__iter__`, `__le__`, `__len__`, `__lt__`, `__mul__`, `__ne__`, `__new__`, `__rmul__`, `__sizeof__`, `count`, `index` Inherited from `object`: `__delattr__`, `__format__`, `__init__`, `__reduce__`, `__reduce_ex__`, `__setattr__`, `__str__`, `__subclasshook__`

Properties
Inherited from `object`: `__class__`

Method Details

### __contains__(self, name) (In operator) |
Return whether the list includes an attribute with the specified name. Returns: `bool` `True` if the list includes the attribute Overrides: tuple.__contains__

### __getitem__(self, i) (Indexing operator) |
Return an item or slice of the attributes list.
    >>> attrs = Attrs([('href', '#'), ('title', 'Foo')])
    >>> attrs[1]
    ('title', 'Foo')
    >>> attrs[1:]
    Attrs([('title', 'Foo')])
Overrides: tuple.__getitem__

### __getslice__(self, i, j) (Slicling operator) |
Return a slice of the attributes list.
    >>> attrs = Attrs([('href', '#'), ('title', 'Foo')])
    >>> attrs[1:]
    Attrs([('title', 'Foo')])
Overrides: tuple.__getslice__

### __or__(self, attrs) (Or operator) |
Return a new instance that contains the attributes in `attrs` in addition to any already existing attributes. Any attributes in the new set that have a value of `None` are removed. Returns: Attrs a new instance with the merged attributes

### __repr__(self) (Representation operator) |
repr(x) Overrides: object.__repr__ (inherited documentation)

### __sub__(self, names) (Subtraction operator) |
Return a new instance with all attributes with a name in `names` are removed. Parameters: `names` - the names of the attributes to remove Returns: Attrs a new instance with the attribute removed

### get(self, name, default=None) |
Return the value of the attribute with the specified name, or the value of the `default` parameter if no such attribute is found. Parameters: `name` - the name of the attribute `default` - the value to return when the attribute does not exist Returns: `object` the attribute value, or the `default` value if that attribute does not exist

### totuple(self) |
Return the attributes as a markup event. The returned event is a TEXT event, the data is the value of all attributes joined together.
    >>> Attrs([('href', '#'), ('title', 'Foo')]).totuple()
    ('TEXT', '#Foo', (None, -1, -1))
Returns: `tuple` a TEXT event