arn

0.1.5 verified Mon Apr 27 auth: no python

A lightweight Python library for parsing and manipulating AWS ARNs (Amazon Resource Names). Version 0.1.5, low activity.

pip install arn

Common errors

error AttributeError: module 'arn' has no attribute 'ARN' ↓

cause Importing the module instead of the class.

fix

Use 'from arn import ARN' or 'import arn; arn.ARN'.

error arn.ArnException: Invalid ARN string ↓

cause The input string does not match the ARN format (e.g., missing 'arn:' prefix).

fix

Ensure the string starts with 'arn:' and follows the pattern 'arn:partition:service:region:account:resource'.

Warnings

gotcha The ARN constructor does not validate that the partition matches known AWS partitions (e.g., 'aws', 'aws-cn', 'aws-us-gov'). It accepts arbitrary strings, so 'arn:foo:...' parses without error. ↓

fix Validate partition manually with a whitelist if needed.

gotcha The library does not support ARNs with resource qualifiers (like 'arn:aws:s3:::bucket/key') via the standard resource attribute; you may need to parse the resource string manually. ↓

fix Use `parsed.resource` and split on '/' or ':' as needed.

Imports

ARN
wrong
```
import arn
```
correct
```
from arn import ARN
```
Imported module does not expose ARN as top-level; must explicitly import the class.

Quickstart

Parse an AWS ARN and access its components.

from arn import ARN

arn_str = os.environ.get('AWS_ARN', 'arn:aws:iam::123456789012:user/JohnDoe')
try:
    parsed = ARN(arn_str)
    print(f'Service: {parsed.service}, Region: {parsed.region}, Account: {parsed.account}, Resource: {parsed.resource}')
except Exception as e:
    print(f'Invalid ARN: {e}')