Package babel :: Module support :: Class LazyProxy

Class LazyProxy

object --+
         |
        LazyProxy

Class for proxy objects that delegate to a specified function to evaluate the actual object.

>>> def greeting(name='world'):
...     return 'Hello, %s!' % name
>>> lazy_greeting = LazyProxy(greeting, name='Joe')
>>> print lazy_greeting
Hello, Joe!
>>> u'  ' + lazy_greeting
u'  Hello, Joe!'
>>> u'(%s)' % lazy_greeting
u'(Hello, Joe!)'

This can be used, for example, to implement lazy translation functions that delay the actual translation until the string is actually used. The rationale for such behavior is that the locale of the user may not always be available. In web applications, you only know the locale when processing a request.

The proxy implementation attempts to be as complete as possible, so that the lazy objects should mostly work as expected, for example for sorting:

>>> greetings = [
...     LazyProxy(greeting, 'world'),
...     LazyProxy(greeting, 'Joe'),
...     LazyProxy(greeting, 'universe'),
... ]
>>> greetings.sort()
>>> for greeting in greetings:
...     print greeting
Hello, Joe!
Hello, universe!
Hello, world!

Instance Methods

__init__(self, func, *args, **kwargs)
x.__init__(...) initializes x; see x.__class__.__doc__ for signature

__contains__(self, key)

__nonzero__(self)

__dir__(self)

__iter__(self)

__len__(self)

__str__(self)
str(x)

__unicode__(self)

__add__(self, other)

__radd__(self, other)

__mod__(self, other)

__rmod__(self, other)

__mul__(self, other)

__rmul__(self, other)

__call__(self, *args, **kwargs)

__lt__(self, other)

__le__(self, other)

__eq__(self, other)

__ne__(self, other)

__gt__(self, other)

__ge__(self, other)

__delattr__(self, name)
x.__delattr__('name') <==> del x.name

__getattr__(self, name)

__setattr__(self, name, value)
x.__setattr__('name', value) <==> x.name = value

__delitem__(self, key)

__getitem__(self, key)

__setitem__(self, key, value)

Inherited from object: __format__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __sizeof__, __subclasshook__

Properties
	value
Inherited from `object`: `__class__`

Method Details

init(self, func, *args, **kwargs)
(Constructor)

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

Overrides: object.__init__: (inherited documentation)

str(self)
(Informal representation operator)

str(x)

Overrides: object.__str__: (inherited documentation)

delattr(self, name)

x.__delattr__('name') <==> del x.name

Overrides: object.__delattr__: (inherited documentation)

setattr(self, name, value)

x.__setattr__('name', value) <==> x.name = value

Overrides: object.__setattr__: (inherited documentation)

Property Details

value

Get Method:: unreachable.value(self)

Class LazyProxy

__init__(self, func, *args, **kwargs) (Constructor)

__str__(self) (Informal representation operator)

__delattr__(self, name)

__setattr__(self, name, value)

value

init(self, func, *args, **kwargs)
(Constructor)

str(self)
(Informal representation operator)

delattr(self, name)

setattr(self, name, value)