This module implements an RFC 5424 IETF Syslog Protocol parser in Python, using the pyparsing parser-generator. It should work on Python 2.7 or Python 3.3+.
The file example_syslog_server.py contains a fully-functional Syslog server which will receivemessages on a UNIX domain socket and print them to stdout as JSON blobs.
On a fairly modern system (Xeon E3-1270v3), it takes about 700µs to parse a single syslog message and construct a SyslogMessage object (which is to say, you should be able to parse about 1400 per second with a single-threaded process). Effectively all of the time is spent in pyparsing, and packrat only makes it worse. Are you really in that much of a rush, anyway?