Bastion
— 对象访问限定
¶
Deprecated since version 2.6:
The
Bastion
module has been removed in Python 3.
Changed in version 2.3: Disabled module.
注意
The documentation has been left in place to help in reading old code that uses the module.
According to the dictionary, a bastion is “a fortified area or position”, or “something that is considered a stronghold.” It’s a suitable name for this module, which provides a way to forbid access to certain attributes of an object. It must always be used with the
rexec
module, in order to allow restricted-mode programs access to certain safe attributes of an object, while denying access to other, unsafe attributes.
Bastion.
Bastion
(
对象
[
,
filter
[
,
名称
[
,
class
]
]
]
)
¶
Protect the object
object
, returning a bastion for the object. Any attempt to access one of the object’s attributes will have to be approved by the
filter
function; if the access is denied an
AttributeError
exception will be raised.
If present,
filter
must be a function that accepts a string containing an attribute name, and returns true if access to that attribute will be permitted; if
filter
returns false, the access is denied. The default filter denies access to any function beginning with an underscore (
'_'
). The bastion’s string representation will be
<Bastion for name>
if a value for
name
is provided; otherwise,
repr(object)
会被使用。
class
, if present, should be a subclass of
BastionClass
; see the code in
bastion.py
for the details. Overriding the default
BastionClass
will rarely be required.
Bastion.
BastionClass
(
getfunc
,
名称
)
¶
Class which actually implements bastion objects. This is the default class used by
Bastion()
。
getfunc
parameter is a function which returns the value of an attribute which should be exposed to the restricted execution environment when called with the name of the attribute as the only parameter.
name
is used to construct the
repr()
的
BastionClass
实例。