Dicts¶
Todo
intro
set()
Policy¶
Todo
strict, duck, etc.
Validation¶
If descent_validators
is defined, these validators
will be run first, before member elements are validated.
If validators
is defined, these
validators will be run after member elements are validated.
Dict
¶
-
class
Dict
(value=Unspecified, **kw)¶ Bases:
flatland.schema.containers.Mapping
,dict
A mapping Container with named members.
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classmethod
from_object
(obj, include=None, omit=None, rename=None, **kw)¶ Return an element initialized with an object’s attributes.
Parameters: - obj – any object
- include – optional, an iterable of attribute names to pull from obj, if present on the object. Only these attributes will be included.
- omit – optional, an iterable of attribute names to ignore on obj. All other attributes matching a named field on the mapping will be included.
- rename – optional, a mapping of attribute-to-field name transformations. Attributes specified in the mapping will be included regardless of include or omit.
- **kw – keyword arguments will be passed to the element’s constructor.
include and omit are mutually exclusive.
This is a convenience constructor for
set_by_object()
:element = cls(**kw) element.set_by_object(obj, include, omit, rename)
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of
(*fields)¶ Todo
doc of()
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set
(value, policy=None)¶ Todo
doc set()
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set_by_object
(obj, include=None, omit=None, rename=None)¶ Set fields with an object’s attributes.
Parameters: - obj – any object
- include – optional, an iterable of attribute names to pull from obj, if present on the object. Only these attributes will be included.
- omit – optional, an iterable of attribute names to ignore on obj. All other attributes matching a named field on the mapping will be included.
- rename – optional, a mapping of attribute-to-field name transformations. Attributes specified in the mapping will be included regardless of include or omit.
include and omit are mutually exclusive.
Sets fields on self, using as many attributes as possible from obj. Object attributes that do not correspond to field names are ignored.
Mapping instances have two corresponding methods useful for round-tripping values in and out of your domain objects.
update_object()
performs the inverse ofset_object()
, andslice()
is useful for constructing new objects.>>> user = User('biff', 'secret') >>> form = UserForm() >>> form.set_by_object(user) >>> form['login'].value u'biff' >>> form['password'] = u'new-password' >>> form.update_object(user, omit=['verify_password']) >>> user.password u'new-password' >>> user_keywords = form.slice(omit=['verify_password'], key=str) >>> sorted(user_keywords.keys()) ['login', 'password'] >>> new_user = User(**user_keywords)
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slice
(include=None, omit=None, rename=None, key=None)¶ Return a
dict
containing a subset of the element’s values.
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update_object
(obj, include=None, omit=None, rename=None, key=<function identifier_transform>)¶ Update an object’s attributes using the element’s values.
Produces a
slice()
using include, omit, rename and key, and sets the selected attributes on obj usingsetattr
.Returns: nothing. obj is modified directly.
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classmethod
SparseDict
¶
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class
SparseDict
(value=Unspecified, **kw)¶ Bases:
flatland.schema.containers.Dict
A Mapping which may contain a subset of the schema’s allowed keys.
This differs from
Dict
in that new instances are not created with empty values for all possible keys. In addition, mutating operations are allowed so long as the operations operate within the schema. For example, you maypop()
anddel
members of the mapping.-
clear
() → None. Remove all items from D.¶
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may_contain
(key)¶ Return True if the element schema allows a field named key.
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pop
(k[, d]) → v, remove specified key and return the corresponding value.¶ If key is not found, d is returned if given, otherwise KeyError is raised
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popitem
() → (k, v), remove and return some (key, value) pair as a¶ 2-tuple; but raise KeyError if D is empty.
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set_default
()¶ set() the element to the schema default.
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setdefault
(k[, d]) → D.get(k,d), also set D[k]=d if k not in D¶
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