See Changelog.

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changes:

• Modify validators for conlist and conset to not have always=True, #1682 by @samuelcolvin
• add port check to AnyUrl (can't exceed 65536) ports are 16 insigned bits: 0 <= port <= 2**16-1 src: rfc793 header format, #1654 by @flapili
• Document default regex anchoring semantics, #1648 by @yurikhan
• Use chain.from_iterable in class_validators.py. This is a faster and more idiomatic way of using itertools.chain. Instead of computing all the items in the iterable and storing them in memory, they are computed one-by-one and never stored as a huge list. This can save on both runtime and memory space, #1642 by @cool-RR
• Add conset(), analogous to conlist(), #1623 by @patrickkwang
• make pydantic errors (un)pickable, #1616 by @PrettyWood
• Allow custom encoding for dotenv files, #1615 by @PrettyWood
• Ensure SchemaExtraCallable is always defined to get type hints on BaseConfig, #1614 by @PrettyWood
• Update datetime parser to support negative timestamps, #1600 by @mlbiche
• Update mypy, remove AnyType alias for Type[Any], #1598 by @samuelcolvin
• Adjust handling of root validators so that errors are aggregated from all failing root validators, instead of reporting on only the first root validator to fail, #1586 by @beezee
• Make __modify_schema__ on Enums apply to the enum schema rather than fields that use the enum, #1581 by @therefromhere
• Fix behavior of __all__ key when used in conjunction with index keys in advanced include/exclude of fields that are sequences, #1579 by @xspirus
• Subclass validators do not run when referencing a List field defined in a parent class when each_item=True. Added an example to the docs illustrating this, #1566 by @samueldeklund
• change schema.field_class_to_schema to support frozenset in schema, #1557 by @wangpeibao
• Call __modify_schema__ only for the field schema, #1552 by @PrettyWood
• Move the assignment of field.validate_always in fields.py so the always parameter of validators work on inheritance, #1545 by @dcHHH
• Added support for UUID instantiation through 16 byte strings such as b'\x12\x34\x56\x78' * 4. This was done to support BINARY(16) columns in sqlalchemy, #1541 by @shawnwall
• Add a test assertion that default_factory can return a singleton, #1523 by @therefromhere
• Add NameEmail.__eq__ so duplicate NameEmail instances are evaluated as equal, #1514 by @stephen-bunn
• Add datamodel-code-generator link in pydantic document site, #1500 by @koxudaxi
• Added a "Discussion of Pydantic" section to the documentation, with a link to "Pydantic Introduction" video by Alexander Hultnér, #1499 by @hultner
• Avoid some side effects of default_factory by calling it only once if possible and by not setting a default value in the schema, #1491 by @PrettyWood
• Added docs about dumping dataclasses to JSON, #1487 by @mikegrima
• Make BaseModel.__signature__ class-only, so getting __signature__ from model instance will raise AttributeError, #1466 by @MrMrRobat
• include 'format': 'password' in the schema for secret types, #1424 by @atheuz
• Modify schema constraints on ConstrainedFloat so that exclusiveMinimum and minimum are not included in the schema if they are equal to -math.inf and exclusiveMaximum and maximum are not included if they are equal to math.inf, #1417 by @vdwees
• Squash internal __root__ dicts in .dict() (and, by extension, in .json()), #1414 by @patrickkwang
• Move const validator to post-validators so it validates the parsed value, #1410 by @selimb
• Fix model validation to handle nested literals, e.g. Literal['foo', Literal['bar']], #1364 by @DBCerigo
• Remove user_required = True from RedisDsn, neither user nor password are required, #1275 by @samuelcolvin
• Remove extra allOf from schema for fields with Union and custom Field, #1209 by @mostaphaRoudsari
• Updates OpenAPI schema generation to output all enums as separate models. Instead of inlining the enum values in the model schema, models now use a $ref property to point to the enum definition, #1173 by @calvinwyoung