4.0.0

4.0.0 - 2025-10-06

Added

• Support DictConfigurator prefixes for rename_fields and static_fields. #45
  • Allows using values like ext://sys.stderr in fileConfig/dictConfig value fields.
• Support comma seperated lists for Formatter fmt (style=",") e.g. "asctime,message,levelname" #15
  • Note that this style is specific to python-json-logger and thus care should be taken not to pass this format to other logging Formatter implementations.
• Supports sequences of strings (e.g. lists and tuples) of field names for Formatter fmt. #16

Changed

• Rename pythonjsonlogger.core.LogRecord and log_record arguments to avoid confusion / overlapping with logging.LogRecord. #38
  • Affects arguments to pythonjsonlogger.core.BaseJsonFormatter (and any child classes).
    • serialize_log_record
    • add_fields
    • jsonify_log_record
    • process_log_record
  • Note: functions referring to log_record have not had their function name changed.

Removed

• Remove support for providing strings instead of objects when instantiating formatters. Instead use the DictConfigurator ext:// prefix format when using fileConfig/dictConfig. #47
  • Affects pythonjsonlogger.json.JsonFormatter: json_default, json_encoder, json_serializer.
  • Affects pythonjsonlogger.orjson.OrjsonFormatter: json_default.
  • Affects pythonjsonlogger.msgspec.MsgspecFormatter: json_default.

Thanks @rubensa

v4.0.0.rc1

4.0.0.rc1 - 2025-09-07

Added

• Support DictConfigurator prefixes for rename_fields and static_fields. #45
  • Allows using values like ext://sys.stderr in fileConfig/dictConfig value fields.
• Support comma seperated lists for Formatter fmt (style=",") e.g. "asctime,message,levelname" #15
  • Note that this style is specific to python-json-logger and thus care should be taken not to pass this format to other logging Formatter implementations.
• Supports sequences of strings (e.g. lists and tuples) of field names for Formatter fmt. #16

Changed

• Rename pythonjsonlogger.core.LogRecord and log_record arguments to avoid confusion / overlapping with logging.LogRecord. #38
  • Affects arguments to pythonjsonlogger.core.BaseJsonFormatter (and any child classes).
    • serialize_log_record
    • add_fields
    • jsonify_log_record
    • process_log_record
  • Note: functions referring to log_record have not had their function name changed.

Removed

• Remove support for providing strings instead of objects when instantiating formatters. Instead use the DictConfigurator ext:// prefix format when using fileConfig/dictConfig. #47
  • Affects pythonjsonlogger.json.JsonFormatter: json_default, json_encoder, json_serializer.
  • Affects pythonjsonlogger.orjson.OrjsonFormatter: json_default.
  • Affects pythonjsonlogger.msgspec.MsgspecFormatter: json_default.

Thanks @rubensa

3.3.0

3.3.0 - 2025-03-06

Added

• exc_info_as_array and stack_info_as_array options are added to pythonjsonlogger.core.BaseJsonFormatter allowing both to be encoded as list of lines instead of a single multi-line string. #35

Security

• Remove msgspec-python313-pre from dev dependencies preventing potential RCE. Details: GHSA-wmxh-pxcx-9w24

Thanks @1hakusai1 and @omnigodz

3.2.1

3.2.1 - 2024-12-16

Fixed

• Import error on import pythonjsonlogger.jsonlogger #29

3.2.0

3.2.0 - 2024-12-11

Changed

• pythonjsonlogger.[ORJSON,MSGSPEC]_AVAILABLE no longer imports the respective package when determining availability.
• pythonjsonlogger.[orjson,msgspec] now throws a pythonjsonlogger.exception.MissingPackageError when required libraries are not available. These contain more information about what is missing whilst still being an ImportError.
• defaults parameter is no longer ignored and now conforms to the standard library. Setting a defaults dictionary will add the specified keys if the those keys do not exist in a record or weren't passed by the extra parameter when logging a message.
• typing_extensions is only installed on Python version < 3.10.
• Support Python 3.13
  • msgspec has only been tested against pre-release versions.

Thanks @cjwatson and @bharel

v3.1.0

3.1.0 - 2023-05-28

This splits common funcitonality out to allow supporting other JSON encoders. Although this is a large refactor, backwards compatibility has been maintained.

Added

• pythonjsonlogger.core - more details below.
• pythonjsonlogger.defaults module that provides many functions for handling unsupported types.
• Orjson encoder support via pythonjsonlogger.orjson.OrjsonFormatter with the following additions:
  • bytes are URL safe base64 encoded.
  • Exceptions are "pretty printed" using the exception name and message e.g. "ValueError: bad value passed"
  • Enum values use their value, Enum classes now return all values as a list.
  • Tracebacks are supported
  • Classes (aka types) are support
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
• MsgSpec encoder support via pythonjsonlogger.msgspec.MsgspecFormatter with the following additions:
  • Exceptions are "pretty printed" using the exception name and message e.g. "ValueError: bad value passed"
  • Enum classes now return all values as a list.
  • Tracebacks are supported
  • Classes (aka types) are support
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
  • Note: msgspec only supprts enum values of type int or str jcrist/msgspec#680

Changed

• pythonjsonlogger.jsonlogger has been moved to pythonjsonlogger.json with core functionality moved to pythonjsonlogger.core.
• pythonjsonlogger.core.BaseJsonFormatter properly supports all logging.Formatter arguments:
  • fmt is unchanged.
  • datefmt is unchanged.
  • style can now support non-standard arguments by setting validate to False
  • validate allows non-standard style arguments or prevents calling validate on standard style arguments.
  • default is ignored.
• pythonjsonlogger.json.JsonFormatter default encodings changed:
  • bytes are URL safe base64 encoded.
  • Exception formatting detected using BaseException instead of Exception. Now "pretty prints" the exception using the exception name and message e.g. "ValueError: bad value passed"
  • Dataclasses are now supported
  • Enum values now use their value, Enum classes now return all values as a list.
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
• Renaming fields now preserves order (#7) and ignores missing fields (#6).
• Documentation
  • Generated documentation using mkdocs is stored in docs/
  • Documentation within README.md has been moved to docs/index.md and docs/qucikstart.md.
  • CHANGELOG.md has been moved to docs/change-log.md
  • SECURITY.md has been moved and replaced with a symbolic link to docs/security.md.

Deprecated

• pythonjsonlogger.jsonlogger is now pythonjsonlogger.json
• pythonjsonlogger.jsonlogger.RESERVED_ATTRS is now pythonjsonlogger.core.RESERVED_ATTRS.
• pythonjsonlogger.jsonlogger.merge_record_extra is now pythonjsonlogger.core.merge_record_extra.

Removed

• Python 3.7 support dropped
• pythonjsonlogger.jsonlogger.JsonFormatter._str_to_fn replaced with pythonjsonlogger.core.str_to_object.

v3.1.0.rc3

3.1.0.rc3 - 2023-05-03

This splits common funcitonality out to allow supporting other JSON encoders. Although this is a large refactor, backwards compatibility has been maintained.

Added

• .core - more details below.
• .defaults module that provides many functions for handling unsupported types.
• Orjson encoder support via .orjson.OrjsonFormatter with the following additions:
  • bytes are URL safe base64 encoded.
  • Exceptions are "pretty printed" using the exception name and message e.g. "ValueError: bad value passed"
  • Enum values use their value, Enum classes now return all values as a list.
  • Tracebacks are supported
  • Classes (aka types) are support
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
• MsgSpec encoder support via .msgspec.MsgspecFormatter with the following additions:
  • Exceptions are "pretty printed" using the exception name and message e.g. "ValueError: bad value passed"
  • Enum classes now return all values as a list.
  • Tracebacks are supported
  • Classes (aka types) are support
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
  • Note: msgspec only supprts enum values of type int or str jcrist/msgspec#680

Changed

• .jsonlogger has been moved to .json with core functionality moved to .core.
• .core.BaseJsonFormatter properly supports all logging.Formatter arguments:
  • fmt is unchanged.
  • datefmt is unchanged.
  • style can now support non-standard arguments by setting validate to False
  • validate allows non-standard style arguments or prevents calling validate on standard style arguments.
  • default is ignored.
• .json.JsonEncoder default encodings changed:
  • bytes are URL safe base64 encoded.
  • Exception formatting detected using BaseException instead of Exception. Now "pretty prints" the exception using the exception name and message e.g. "ValueError: bad value passed"
  • Dataclasses are now supported
  • Enum values now use their value, Enum classes now return all values as a list.
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
• Renaming fields now preserves order (#7) and ignores missing fields (#6).

Deprecated

• .jsonlogger is now .json
• .jsonlogger.RESERVED_ATTRS is now .core.RESERVED_ATTRS.
• .jsonlogger.merge_record_extra is now .core.merge_record_extra.

Removed

• Python 3.7 support dropped
• .jsonlogger.JsonFormatter._str_to_fn replaced with .core.str_to_object.

v3.1.0.rc2

3.1.0.rc2 - 2023-05-03

This splits common funcitonality out to allow supporting other JSON encoders. Although this is a large refactor, backwards compatibility has been maintained.

Added

• .core - more details below.
• .defaults module that provides many functions for handling unsupported types.
• Orjson encoder support via .orjson.OrjsonFormatter with the following additions:
  • bytes are URL safe base64 encoded.
  • Exceptions are "pretty printed" using the exception name and message e.g. "ValueError: bad value passed"
  • Enum values use their value, Enum classes now return all values as a list.
  • Tracebacks are supported
  • Classes (aka types) are support
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
• MsgSpec encoder support via .msgspec.MsgspecFormatter with the following additions:
  • Exceptions are "pretty printed" using the exception name and message e.g. "ValueError: bad value passed"
  • Enum classes now return all values as a list.
  • Tracebacks are supported
  • Classes (aka types) are support
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__
  • Note: msgspec only supprts enum values of type int or str jcrist/msgspec#680

Changed

• .jsonlogger has been moved to .json with core functionality moved to .core.
• .core.BaseJsonFormatter properly supports all logging.Formatter arguments:
  • fmt is unchanged.
  • datefmt is unchanged.
  • style can now support non-standard arguments by setting validate to False
  • validate allows non-standard style arguments or prevents calling validate on standard style arguments.
  • default is ignored.
• .json.JsonEncoder default encodings changed:
  • bytes are URL safe base64 encoded.
  • Exception formatting detected using BaseException instead of Exception. Now "pretty prints" the exception using the exception name and message e.g. "ValueError: bad value passed"
  • Dataclasses are now supported
  • Enum values now use their value, Enum classes now return all values as a list.
  • Will fallback on __str__ if available, else __repr__ if available, else will use __could_not_encode__

Deprecated

• .jsonlogger is now .json
• .jsonlogger.RESERVED_ATTRS is now .core.RESERVED_ATTRS.
• .jsonlogger.merge_record_extra is now .core.merge_record_extra.

Removed

• Python 3.7 support dropped
• .jsonlogger.JsonFormatter._str_to_fn replaced with .core.str_to_object.

v3.1.0.rc1

3.1.0.rc1 - 2023-05-03

This splits common funcitonality out to allow supporting other JSON encoders. Although this is a large refactor, backwards compatibility has been maintained.

Added

• .core - more details below.
• Orjson encoder support via .orjson.OrjsonFormatter.
• MsgSpec encoder support via .msgspec.MsgspecFormatter.

Changed

• .jsonlogger has been moved to .json with core functionality moved to .core.
• .core.BaseJsonFormatter properly supports all logging.Formatter arguments:
  • fmt is unchanged.
  • datefmt is unchanged.
  • style can now support non-standard arguments by setting validate to False
  • validate allows non-standard style arguments or prevents calling validate on standard style arguments.
  • default is ignored.

Deprecated

• .jsonlogger is now .json
• .jsonlogger.RESERVED_ATTRS is now .core.RESERVED_ATTRS.
• .jsonlogger.merge_record_extra is now .core.merge_record_extra.

Removed

• Python 3.7 support dropped
• .jsonlogger.JsonFormatter._str_to_fn replaced with .core.str_to_object.

v3.0.1

3.0.1 - 2023-04-01

Fixes

• Fix spelling of parameter json_serialiser -> json_serializer (#8) - @juliangilbey