Extract a given format field from the given event.

ParametersfieldA string describing a format field or log key. This is the text that would normally fall between a pair of curly braces in a format string: for example, "key[2].attribute". If a conversion is specified (the thing after the "!" character in a format field) then the result will always be unicode. (type: str (native string))
eventA log event. (type: dict)
ReturnsA value extracted from the field. (type: object)
RaisesKeyErrorif the field is not found in the given event.
API Documentation for Twisted, generated by pydoctor at 2015-11-29 11:40:45.