skip to navigation
skip to content

Not Logged In

colander 1.0b1

A simple schema-based serialization and deserialization library

An extensible package which can be used to:

  • deserialize and validate a data structure composed of strings, mappings, and lists.
  • serialize an arbitrary data structure to a data structure composed of strings, mappings, and lists.

It runs on Python 2.6, 2.7, 3.2, and 3.3.

Please see http://docs.pylonsproject.org/projects/colander/en/latest/ for further documentation.

See https://github.com/Pylons/colander for in-development version.

1.0b1 (2013-09-01)

Bug Fixes

  • In 1.0a1, there was a change merged from https://github.com/Pylons/colander/pull/73 which made it possible to supply None as the default value for a String type, and upon serialization, the value would be rendered as colander.null if the default were used. This confused people who were actually supplying the value None as a default when the associated appstruct had no value, so the change has been reverted. When you supply None as the default argument to a String, the rendered serialize() value will again be 'None'. Sorry.
  • Normalize colander.Function argument message to be msg. This now matches other APIs within Colander. The message argument is now deprecated and a warning will be emitted. https://github.com/Pylons/colander/issues/31 https://github.com/Pylons/colander/issues/64
  • iso8601.py: Convert ValueError (raised by datetime) into ParseErrorr in parse_date, so that the validation machinery upstream handles it properly.
  • iso8601.py: Correctly parse datetimes with a timezone of Z even when the default_timezone is set. These previously had the default timezone.
  • colander.String schema type now raises colander.Invalid when trying to deserialize a non-string item. See https://github.com/Pylons/colander/issues/100

Features

  • Add colander.List type, modeled on deform.List: this type preserves ordering, and allows duplicates.

  • It is now possible to use the value colander.drop as the default value for items that are subitems of a mapping. If colander.drop is used as the default for a subnode of a mapping schema, and the mapping appstruct being serialized does not have a value for that schema node, the value will be omitted from the serialized mapping. For instance, the following script, when run would not raise an assertion error:

    class What(colander.MappingSchema):
      thing = colander.SchemaNode(colander.String(), default=colander.drop)
    
    result = What().serialize({}) # no "thing" in mapping
    assert result == {}
    
  • The typ of a SchemaNode can optionally be pased in as a keyword argument. See https://github.com/Pylons/colander/issues/90

1.0a5 (2013-05-31)

1.0a4 (2013-05-21)

  • Loosen Email validator regex (permit apostrophes, bang, etc in localpart).
  • Allow for timezone info objects to be pickled and unpickled "more correctly" (Use '__getinitargs__' to provide unpickling-only defaults). See https://github.com/Pylons/colander/pull/108.

1.0a3 (2013-05-16)

Features

  • Support spec-mandated truncations of ISO-8601 timezones.
  • Support spec-mandated truncations of ISO-8601 datetimes.
  • Allow specifying custom representations of values for boolean fields.

Bug Fixes

  • Ensure that colander.iso8601.FixedOffset instances can be unpickled.
  • Avoid validating strings as sequences under Py3k.
  • Sync documentation with 0.9.9 change to use insert_before rather than schema_order. See https://github.com/Pylons/colander/issues/104

1.0a2 (2013-01-30)

Features

  • Add colander.ContainsOnly and colander.url validators.
  • Add colander.instantiate to help define schemas containing mappings and sequences more succinctly.

1.0a1 (2013-01-10)

Bug Fixes

Features

  • Add colander.Set type, ported from deform.Set

  • Add Python 3.3 to tox configuration and use newer tox testing regime (setup.py dev).

  • Add Python 3.3 Trove classifier.

  • Calling bind on a schema node e.g. cloned_node = somenode.bind(a=1, b=2) on a schema node now results in the cloned node having a bindings attribute of the value {'a':1, 'b':2}.

  • It is no longer necessary to pass a typ argument to a SchemaNode constructor if the node class has a schema_type callable as a class attribute which, when called with no arguments, returns a schema type. This callable will be called to obtain the schema type if a typ is not supplied to the constructor. The default SchemaNode object's schema_type callable raises a NotImplementedError when it is called.

  • SchemaNode now has a raise_invalid method which accepts a message and raises a colander.Invalid exception using self as the node and the message as its message.

  • It is now possible and advisable to subclass SchemaNode in order to create a bundle of default node behavior. The subclass can define the following methods and attributes: preparer, validator, default, missing, name, title, description, widget, and after_bind.

    For example, the older, more imperative style that looked like this still works, of course:

    from colander import SchemaNode
    
    ranged_int = colander.SchemaNode(
        validator=colander.Range(0, 10),
        default = 10,
        title='Ranged Int'
        )
    

    But you can alternately now do something like this:

    from colander import SchemaNode
    
    class RangedIntSchemaNode(SchemaNode):
        validator = colander.Range(0, 10)
        default = 10
        title = 'Ranged Int'
    
    ranged_int = RangedInt()
    

    Values that are expected to be callables can now alternately be methods of the schemanode subclass instead of plain attributes:

    from colander import SchemaNode
    
    class RangedIntSchemaNode(SchemaNode):
        default = 10
        title = 'Ranged Int'
    
        def validator(self, node, cstruct):
           if not 0 < cstruct < 10:
               raise colander.Invalid(node, 'Must be between 0 and 10')
    
    ranged_int = RangedInt()
    

    Note that when implementing a method value such as validator that expects to receive a node argument, node must be provided in the call signature, even though node will almost always be the same as self. This is because Colander simply treats the method as another kind of callable, be it a method, or a function, or an instance that has a __call__ method. It doesn't care that it happens to be a method of self, and it needs to support callables that are not methods, so it sends node in regardless.

    You can't currently use method definitions as colander.deferred callables. For example this will not work:

    from colander import SchemaNode
    
    class RangedIntSchemaNode(SchemaNode):
        default = 10
        title = 'Ranged Int'
    
        @colander.deferred
        def validator(self, node, kw):
           request = kw['request']
           def avalidator(node, cstruct):
               if not 0 < cstruct < 10:
                   if request.user != 'admin':
                       raise colander.Invalid(node, 'Must be between 0 and 10')
           return avalidator
    
    ranged_int = RangedInt()
    bound_ranged_int = ranged_int.bind(request=request)
    

    This will result in:

    TypeError: avalidator() takes exactly 3 arguments (2 given)
    

    However, if you treat the thing being decorated as a function instead of a method (remove the self argument from the argument list), it will indeed work):

    from colander import SchemaNode
    
    class RangedIntSchemaNode(SchemaNode):
        default = 10
        title = 'Ranged Int'
    
        @colander.deferred
        def validator(node, kw):
           request = kw['request']
           def avalidator(node, cstruct):
               if not 0 < cstruct < 10:
                   if request.user != 'admin':
                       raise colander.Invalid(node, 'Must be between 0 and 10')
           return avalidator
    
    ranged_int = RangedInt()
    bound_ranged_int = ranged_int.bind(request=request)
    

    In previous releases of Colander, the only way to defer the computation of values was via the colander.deferred decorator. In this release, however, you can instead use the bindings attribute of self to obtain access to the bind parameters within values that are plain old methods:

    from colander import SchemaNode
    
    class RangedIntSchemaNode(SchemaNode):
        default = 10
        title = 'Ranged Int'
    
        def validator(self, node, cstruct):
           request = self.bindings['request']
           if not 0 < cstruct < 10:
               if request.user != 'admin':
                   raise colander.Invalid(node, 'Must be between 0 and 10')
    
    ranged_int = RangedInt()
    bound_range_int = ranged_int.bind(request=request)
    

    If the things you're trying to defer aren't callables like validator, but they're instead just plain attributes like missing or default, instead of using a colander.deferred, you can use after_bind to set attributes of the schemanode that rely on binding variables:

    from colander import SchemaNode
    
    class UserIdSchemaNode(SchemaNode):
        title = 'User Id'
    
        def after_bind(self, node, kw):
            self.default = kw['request'].user.id
    

    You can override the default values of a schemanode subclass in its constructor:

    from colander import SchemaNode
    
    class RangedIntSchemaNode(SchemaNode):
        default = 10
        title = 'Ranged Int'
        validator = colander.Range(0, 10)
    
    ranged_int = RangedInt(validator=colander.Range(0, 20))
    

    In the above example, the validation will be done on 0-20, not 0-10.

    If a schema node name conflicts with a schema value attribute name on the same class, you can work around it by giving the schema node a bogus name in the class definition but providing a correct name argument to the schema node constructor:

    from colander import SchemaNode, Schema
    
    class SomeSchema(Schema):
        title = 'Some Schema'
        thisnamewillbeignored = colander.SchemaNode(
                                            colander.String(),
                                            name='title'
                                            )
    

    Note that such a workaround is only required if the conflicting names are attached to the exact same class definition. Colander scrapes off schema node definitions at each class' construction time, so it's not an issue for inherited values. For example:

    from colander import SchemaNode, Schema
    
    class SomeSchema(Schema):
        title = colander.SchemaNode(colander.String())
    
    class AnotherSchema(SomeSchema):
        title = 'Some Schema'
    
    schema = AnotherSchema()
    

    In the above example, even though the title = 'Some Schema' appears to override the superclass' title SchemaNode, a title SchemaNode will indeed be present in the child list of the schema instance (schema['title'] will return the title SchemaNode) and the schema's title attribute will be Some Schema (schema.title will return Some Schema).

    Normal inheritance rules apply to class attributes and methods defined in a schemanode subclass. If your schemanode subclass inherits from another schemanode class, your schemanode subclass' methods and class attributes will override the superclass' methods and class attributes.

    Ordering of child schema nodes when inheritance is used works like this: the "deepest" SchemaNode class in the MRO of the inheritance chain is consulted first for nodes, then the next deepest, then the next, and so on. So the deepest class' nodes come first in the relative ordering of schema nodes, then the next deepest, and so on. For example:

    class One(colander.Schema):
        a = colander.SchemaNode(
            colander.String(),
            id='a1',
            )
        b = colander.SchemaNode(
            colander.String(),
            id='b1',
            )
        d = colander.SchemaNode(
            colander.String(),
            id='d1',
            )
    
    class Two(One):
        a = colander.SchemaNode(
            colander.String(),
            id='a2',
            )
        c = colander.SchemaNode(
            colander.String(),
            id='c2',
            )
        e = colander.SchemaNode(
            colander.String(),
            id='e2',
            )
    
    class Three(Two):
        b = colander.SchemaNode(
            colander.String(),
            id='b3',
            )
        d = colander.SchemaNode(
            colander.String(),
            id='d3',
            )
        f = colander.SchemaNode(
            colander.String(),
            id='f3',
            )
    
    three = Three()
    

    The ordering of child nodes computed in the schema node three will be ['a2', 'b3', 'd3', 'c2', 'e2', 'f3']. The ordering starts a1, b1, d1 because that's the ordering of nodes in One, and One is the deepest SchemaNode in the inheritance hierarchy. Then it processes the nodes attached to Two, the next deepest, which causes a1 to be replaced by a2, and c2 and e2 to be appended to the node list. Then finally it processes the nodes attached to Three, which causes b1 to be replaced by b3, and d1 to be replaced by d3, then finally f is appended.

    Multiple inheritance works the same way:

    class One(colander.Schema):
        a = colander.SchemaNode(
            colander.String(),
            id='a1',
            )
        b = colander.SchemaNode(
            colander.String(),
            id='b1',
            )
        d = colander.SchemaNode(
            colander.String(),
            id='d1',
            )
    
    class Two(colander.Schema):
        a = colander.SchemaNode(
            colander.String(),
            id='a2',
            )
        c = colander.SchemaNode(
            colander.String(),
            id='c2',
            )
        e = colander.SchemaNode(
            colander.String(),
            id='e2',
            )
    
    class Three(Two, One):
        b = colander.SchemaNode(
            colander.String(),
            id='b3',
            )
        d = colander.SchemaNode(
            colander.String(),
            id='d3',
            )
        f = colander.SchemaNode(
            colander.String(),
            id='f3',
            )
    
    three = Three()
    

    The resulting node ordering of three is the same as the single inheritance example: ['a2', 'b3', 'd3', 'c2', 'e2', 'f3'] due to the MRO deepest-first ordering (One, then Two, then Three).

Backwards Incompatibilities

  • Passing non-SchemaNode derivative instances as *children into a SchemaNode constructor is no longer supported. Symptom: AttributeError: name when constructing a SchemaNode.

0.9.9 (2012-09-24)

Features

  • Allow the use of missing=None for Number. See https://github.com/Pylons/colander/pull/59 .
  • Create a colander.Money type that is a Decimal type with two-decimal-point precision rounded-up.
  • Allow quant and rounding args to colander.Decimal constructor.
  • luhnok validator added (credit card luhn mod10 validator).
  • Add an insert method to SchemaNode objects.
  • Add an insert_before method to SchemaNode objects.
  • Better class-based mapping schema inheritance model.
    • A node declared in a subclass of a mapping schema superclass now overrides any node with the same name inherited from any superclass. Previously, it just repeated and didn't override.
    • An insert_before keyword argument may be passed to a SchemaNode constructor. This is a string naming a node in a superclass. A node with an insert_before will be placed before the named node in a parent mapping schema.
  • The preparer= argument to SchemaNodes may now be a sequence of preparers.
  • Added a cstruct_children method to SchemaNode.
  • A new cstruct_children API should exist on schema types. If SchemaNode.cstruct_children is called on a node with a type that does not have a cstruct_children method, a deprecation warning is emitted and [] is returned (this may or may not be the correct value for your custom type).

Backwards Incompatibilities

  • The inheritance changes required a minor backwards incompatibility: calling __setitem__ on a SchemaNode will no longer raise KeyError when attempting to set a subnode into a node that doesn't already have an existing subnode by that name. Instead, the subnode will be appended to the child list.

Documentation

  • A "Schema Inheritance" section was added to the Basics chapter documentation.

0.9.8 (2012-04-27)

  • False evaluating values are now serialized to colander.null for String, Date, and Time. This resolves the issue where a None value would be rendered as 'None' for String, and missing='None' was not possible for Date, Datetime, and Time. See https://github.com/Pylons/colander/pull/1 .
  • Updated Brazilian Portugese translations.
  • Updated Japanese translations.
  • Updated Russian translations.
  • Fix documentation: 0.9.3 allowed explicitly passing None to DateTime to have no default timezone applied.
  • Add dev and docs setup.py aliases (e.g. python setup.py dev).

0.9.7 (2012-03-20)

0.9.6 (2012-02-14)

  • No longer runs on Python 2.4 or 2.5. Python 2.6+ is now required.
  • Python 3.2 compatibility.
  • Removed a dependency on the iso8601 package (code from the package is now inlined in Colander itself).
  • Added copyright and licensing information for iso8601-derived code to LICENSE.txt.

0.9.5 (2012-01-13)

  • Added Czech translation.
  • Compile pt_BR translation (it was previously uncompiled).
  • Minor docs fixes.
  • Documentation added about flatten and unflatten.

0.9.4 (2011-10-14)

  • flatten now only includes leaf nodes in the flattened dict.
  • flatten does not include a path element for the name of the type node for sequences.
  • unflatten is implemented.
  • Added __setitem__ to SchemaNode, allowing replacement of nodes by name.
  • Added get_value and set_value methods to Schema which allow access and mutation of appstructs using dotted name paths.
  • Add Swedish, French, Chinese translations.

0.9.3 (2011-06-23)

  • Add Time type.
  • Add Dutch translation.
  • Fix documentation: 0.9.2 requires deserialize of types to explicitly deal with the potential to receive colander.null.
  • Use default_tzinfo when deserializing naive datetimes. See https://github.com/Pylons/colander/issues#issue/5.
  • Allow default_tzinfo to be None when creating a colander.DateTime. See https://github.com/Pylons/colander/issues#issue/6.
  • Add the ability to insert a colander.interfaces.Preparer between deserialization and validation. See the Preparing section in the documentation.

0.9.2 (2011-03-28)

  • Added Polish translation, thanks to Jedrzej Nowak.
  • Moved to Pylons Project GitHub (https://github.com/Pylons/colander).
  • Add tox.ini for testing purposes.
  • New API: colander.required. Used as the marker value when a missing argument is left unspecified.
  • Bug fix: if a title argument which is the empty string or None is passed explicitly to a SchemaNode, it is no longer replaced by a title computed from the name.
  • Add SchemaNode.__contains__ to support "name in schema".
  • SchemaNode deserialization now unconditionally calls the schema type's deserialize method to obtain an appstruct before attempting to validate. Third party schema types should now return colander.null if passed a colander.null value or another logically "empty" value as a cstruct during deserialize.

0.9.1 (2010-12-02)

  • When colander.null was unpickled, the reference created during unpickling was not a reference to the singleton but rather a new instance of the colander._null class. This was unintentional, because lots of code checks for if x is colander.null, which will fail across pickling and unpickling. Now the reference created when colander.null is pickled is unpickled as the singleton itself.

0.9 (2010-11-28)

  • SchemaNode constructor now accepts arbitrary keyword arguments. It sets any unknown values within the **kw sequence as attributes of the node object.
  • Added Spanish locale: thanks to Douglas Cerna for the translations!
  • If you use a schema with deferred validator, missing or default attributes, but you use it to perform serialization and deserialization without calling its bind method:
    • If validator is deferred, no validation will be performed.
    • If missing is deferred, the field will be considered required.
    • If default is deferred, the serialization default will be assumed to be colander.null.
  • Undocumented internal API for all type objects: flatten. External type objects should now inherit from colander.SchemaType to get a default implementation.

0.8 (2010/09/08)

  • Docstring fixes to colander.SchemaNode (missing is not the null value when required, it's a special marker value).
  • The concept of "schema binding" was added, which allows for a more declarative-looking spelling of schemas and schema nodes which have dependencies on values available after the schema has already been fully constructed. See the new narrative chapter in the documentation entitled "Schema Binding".
  • The interface of colander.SchemaNode has grown a __delitem__ method. The __iter__, and __getitem__ methods have now also been properly documented.

0.7.3 (2010/09/02)

  • The title of a schema node now defaults to a titleization of the name. Underscores in the name are replaced with empty strings and the first letter of every resulting word is capitalized. Previously the name was not split on underscores, and the entirety of the name was capitalized.
  • A method of the colander.Invalid exception named messages was added. It returns an iterable of error messages using the msg attribute of its related exception node. If the msg attribute is iterable, it is returned. If it is not iterable, a single-element list containing the msg value is returned.

0.7.2 (2010/08/30)

  • Add an colander.SchemaNode.__iter__ method, which iterates over the children nodes of a schema node.
  • The constructor of a colander.SchemaNode now accepts a widget keyword argument, for use by Deform (it is not used internally).

0.7.1 (2010/06/12)

  • Make it possible to use colander.null as a missing argument to colander.SchemaNode for roundtripping purposes.
  • Make it possible to pickle colander.null.

0.7.0

A release centered around normalizing the treatment of default and missing values.

Bug Fixes

  • Allow colander.Regex validator to accept a pattern object instead of just a string.
  • Get rid of circular reference in Invalid exceptions: Invalid exceptions now no longer have a parent attribute. Instead, they have a positional attribute, which signifies that the parent node type of the schema node to which they relate inherits from Positional. This attribute isn't an API; it's used only internally for reporting.
  • Raise a TypeError when bogus keyword arguments are passed to colander.SchemaNode.

Backwards Incompatiblities / New Features

  • missing constructor arg to SchemaNode: signifies deserialization default, disambiguated from default which acted as both serialization and deserialization default previously.

    Changes necessitated / made possible by SchemaNode missing addition:

    • The allow_empty argument of the colander.String type was removed (use missing='' as a wrapper SchemaNode argument instead).
  • New concept: colander.null input to serialization and deserialization. Use of colander.null normalizes serialization and deserialization default handling.

    Changes necessitated / made possible by colander.null addition:

    • partial argument and attribute of colander.MappingSchema has

      been removed; all serializations are partial, and partial deserializations are not necessary.

    • colander.null values are added to the cstruct for partial

      serializations instead of omitting missing node values from the cstruct.

    • colander.null may now be present in serialized and

      deserialized data structures.

    • sdefault attribute of SchemaNode has been removed; we never need to serialize a default anymore.

    • The value colander.null will be passed as appstruct to each type's serialize method when a mapping appstruct doesn't have a corresponding key instead of None, as was the practice previously.

    • The value colander.null will be passed as cstruct to each type's deserialize method when a mapping cstruct doesn't have a corresponding key instead of None, as was the practice previously.

    • Types now must handle colander.null explicitly during serialization.

  • Updated and expanded documentation, particularly with respect to new colander.null handling.

  • The value argument`` to the serialize method of a SchemaNode is now named appstruct. It is no longer a required argument; it defaults to colander.null now.

    The value argument to the deserialize method of a SchemaNode is now named cstruct. It is no longer a required argument; it defaults to colander.null now.

  • The value argument to the serialize method of each built-in type is now named appstruct, and is now required: it is no longer a keyword argument that has a default.

    The value argument to the deserialize method of each built-in type is now named cstruct, and is now required: it is no longer a keyword argument that has a default.

0.6.2 (2010-05-08)

  • The default encoding parameter value to the colander.String type is still None, however its meaning has changed. An encoding of None now means that no special encoding and decoding of Unicode values is done by the String type. This differs from the previous behavior, where None implied that the encoding was utf-8. Pass the encoding as utf-8 specifically to get the older behavior back. This is in support of Deform.
  • The default err_template value attached to the colander.Date and colander.Datetime types was changed. It is now simply Invalid date instead of _('${val} cannot be parsed as an iso8601 date: ${err}'). This is in support of Deform.
  • Fix bug in colander.Boolean that attempted to call .lower on a bool value when a default value was found for the schema node.

0.6.1 (2010-05-04)

  • Add a Decimal type (number type which uses decimal.Decimal as a deserialization target).

0.6.0 (2010-05-02)

  • (Hopefully) fix intermittent datetime-granularity-related test failures.
  • Internationalized error messages. This required some changes to error message formatting, which may impact you if you were feeding colander an error message template.
  • New project dependency: translationstring package for internationalization.
  • New argument to colander.String constructor: allow_empty. This is a boolean representing whether an empty string is a valid value during deserialization, defaulting to False.
  • Add minimal documentation about the composition of a colander.Invalid exception to the narrative docs.
  • Add (existing, but previously non-API) colander.Invalid attributes to its interface within the API documentation.

0.5.2 (2010-04-09)

  • Add Email and Regex validators (courtesy Steve Howe).
  • Raise a colander.Invalid error if a colander.SequenceSchema is created with more than one member.
  • Add Function validator.
  • Fix bug in serialization of non-Unicode values in the String class.
  • Get rid of pserialize in favor of making serialize always partially serialize.
  • Get rid of pdeserialize: it existed only for symmetry. We'll add something like it back later if we need it.

0.5.1 (2010-04-02)

  • The constructor arguments to a the colander.Schema class are now sent to the constructed SchemaNode rather than to the type it represents.
  • Allow colander.Date and colander.DateTime invalid error messages to be customized.
  • Add a pos argument to the colander.Invalid.add method.
  • Add a __setitem__ method to the colander.Invalid class.
  • The colander.Mapping constructor keyword argument unknown_keys has been renamed to unknown.
  • Allow colander.Mapping type to accept a new constructor argument: partial.
  • New interface methods required by types and schema nodes: pserialize and pdeserialize. These partially serialize or partially deserialize a value (the definition of "partial" is up to the type).

0.5 (2010-03-31)

  • 0.4 was mispackaged (CHANGES.txt missing); no code changes from 0.4 however.

0.4 (2010-03-30)

  • Add colander.DateTime and colander.Date data types.
  • Depend on the iso8601 package for date support.

0.3 (2010-03-29)

  • Subnodes of a schema node are now kept in the children attribute rather than the nodes attribute.
  • Add an sdefault property to colander.SchemaNode objects.
  • Add a clone method to colander.SchemaNode objects.
  • Add a __str__ method to the colander.Invalid exception that prints an error summary.
  • Various error message improvements.
  • Add colander.Length validator class.

0.2 (2010-03-23)

  • Make nodetype overrideable.
  • Add __getitem__ to SchemaNode.
  • Fix OneOf message.
  • Capitalize node titles.
  • Deal with empty strings in String, Boolean, and Float types.
  • Introduce description; make title the same as name.
  • Remove copy method from schemanode.
  • Allow schema nodes to have titles.
  • The term "structure" is too overloaded to use for schema purposes: structure -> schema node.
  • Make Sequence more like Tuple and Mapping (it uses a substructure rather than a structure parameter to denote its type).
  • Add __repr__ and copy methods to structure.
  • Add accept_scalar flag to Sequence.

0.1 (2010-03-14)

  • Initial release.
 
File Type Py Version Uploaded on Size
colander-1.0b1.tar.gz (md5) Source 2013-09-01 110KB
  • Downloads (All Versions):
  • 555 downloads in the last day
  • 2800 downloads in the last week
  • 12377 downloads in the last month