Python log util, outputting elastic/filebeat compatible json

log.py

import json
from datetime import datetime, timezone

LEVELS = {
    "emergency": 7,
    "alert": 6,
    "critical": 5,
    "error": 4,
    "warning": 3,
    "notice": 2,
    "info": 1,
    "debug": 0,
}

# Module state, mutated via logConfigure()
type = None
minimumLevel = None


def logConfigure(logType, level):
    if level not in LEVELS.keys():
        raise Exception("log(): logConfigure called with incorrect level")

    global minimumLevel, type
    type = logType
    minimumLevel = level


def log(level, message, userType="ANONYMOUS"):
    if minimumLevel is None:
        raise Exception("log(): minimumLevel is None. Was logConfigure() called?")

    # Don't log if level isn't at least minimumLevel
    if LEVELS[level] < LEVELS[minimumLevel]:
        return

    stmt = {
        "level": level,
        "type": type,
        "message": message,
        "timestamp": datetimeToIso8601(datetime.now()),
        "userType": userType,
    }
    jsonstr = json.dumps(stmt, separators=(",", ":"))  # most compact

    print("[ELASTIC]" + jsonstr)


# ISO 8601: YYYY-MM-DDTHH:mm:ss.sssZ
def datetimeToIso8601(local):
    utc = local.astimezone(timezone.utc)
    millisec = utc.strftime("%f")[:3]
    return utc.strftime("%Y-%m-%dT%H:%M:%S." + millisec + "Z")