Scripting Best Practices

Writing a script is easy; writing a script that survives production is hard. Follow these standards to ensure your automation remains reliable.

1. Robust Error Handling

Never assume a network call or file operation will succeed. Use try-except-finally blocks.

import boto3
from botocore.exceptions import ClientError
 
def delete_s3_bucket(bucket_name):
    s3 = boto3.client('s3')
    try:
        s3.delete_bucket(Bucket=bucket_name)
    except ClientError as e:
        print(f"API Error: {e.response['Error']['Message']}")
    except Exception as e:
        print(f"Unexpected error: {e}")

2. Structured Logging

Stop using print() for production scripts. Use the built-in logging module.

import logging
 
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(levelname)s - %(message)s'
)
 
logging.info("Starting backup process...")
logging.error("Failed to connect to database.")

3. Configuration Management

Don't hardcode variables. Use environment variables or arguments.

Using os.environ

import os
API_KEY = os.environ.get("MY_APP_API_KEY")

Using argparse

import argparse
 
parser = argparse.ArgumentParser()
parser.add_argument("--env", help="Target environment (prod/stage)", required=True)
args = parser.parse_args()
 
print(f"Running in {args.env}")

Checklist for DevOps Scripts

• Does it have basic error handling?
• Are sensitive keys kept out of the code (using env vars)?
• Is there meaningful logging?
• Does it have a help menu (--help)?
• Is the code PEP 8 compliant (readable)?

[!TIP] Use Docstrings Always include a docstring at the top of your function to explain what it does. Future-you (and your teammates) will thank you.