Reference library

Observability & SRE

Structured logging, metrics, tracing, health checks, and SLO-friendly instrumentation.

4 matches

How to Do Structured JSON Line Logging in Python

Create a simple JSON-lines logger that writes one JSON object per line to stdout with timestamp, level, message, and custom context fields.

logging json observability

Python

import json
import sys
from datetime import datetime

class JsonLineLogger:
    def __init__(self, stream=sys.stdout):
        self.stream = stream

    def log(self, level, message, **context):
        record = {
            "timestamp": datetime.utcnow().isoformat() + "Z",
            "level": level,
            "me…

15 0 Open

Observability & SRE easy

How to Do Structured JSON Logging in Python

Create a custom logging formatter that outputs each log entry as a single JSON line with timestamp, level, logger name, and message.

logging json observability

Python

import json
import logging
from datetime import datetime


class JsonFormatter(logging.Formatter):
    def format(self, record):
        log_entry = {
            "timestamp": datetime.utcnow().isoformat() + "Z",
            "level": record.levelname,
            "logger": record.name,
            "message": record.ge…

14 0 Open

Observability & SRE easy

How to Parse Log Lines with Regex in Python

Extracts timestamp, log level, service name, and message from a log line using compiled regex named groups.

regex logging parsing

Python

import re

LOG_PATTERN = re.compile(
    r'^(?P<timestamp>\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}) '
    r'\[(?P<level>\w+)\] '
    r'\((?P<service>[^)]+)\) '
    r'(?P<message>.*)$'
)

def parse_log_line(line: str) -> dict:
    match = LOG_PATTERN.match(line)
    if not match:
        return {"error": "invalid log format…

14 0 Open

Observability & SRE easy

How to Redact Secrets from Log Messages in Python

Build a lightweight RedactingFormatter class that replaces sensitive tokens like passwords and API keys with [REDACTED] before log messages are printed.

redaction logging secrets

Python

class RedactingFormatter:
    def __init__(self, secrets):
        self.secrets = secrets

    def redact(self, message):
        for secret in self.secrets:
            message = message.replace(secret, "[REDACTED]")
        return message

    def format(self, record):
        message = record["message"]
        ret…

12 0 Open

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