pycfmodel

Build Status License

A python model for Cloud Formation scripts.

pycfmodel makes it easier to work with CloudFormation scripts in Python by creating a model comprised of python objects. Objects have various helper functions which help with performing common tasks related to parsing and inspecting CloudFormation scripts.

pip install pycfmodel

Currently Supported

AWSTemplateFormatVersion
Conditions
Description
Mappings
Metadata
Outputs
Parameters
Resources:
- Properties:
  - Policy
  - Policy Document
  - Principal
  - Security Group Egress Prop
  - Security Group Ingress Prop
  - Statement
  - Tag
- EC2 VPC Endpoint Policy
- Generic Resource
- IAM Group
- IAM Managed Policy
- IAM Policy
- IAM Role
- IAM User
- KMS Key
- OpenSearch Service (legacy ElasticSearch resource)
  - Elasticsearch Domain
- OpenSearch Service
  - OpenSearchService Domain
- S3 Bucket
- S3 Bucket Policy
- Security Group
- Security Group Egress
- Security Group Ingress
- SNS Topic Policy
- SQS Queue Policy
- WAFv2 IP Set
Transform

Example

from pycfmodel import parse

template = {
    "AWSTemplateFormatVersion": "2010-09-09",
    "Parameters": {"StarParameter": {"Type": "String", "Default": "*", "Description": "Star Param"}},
    "Resources": {
        "rootRole": {
            "Type": "AWS::IAM::Role",
            "Properties": {
                "AssumeRolePolicyDocument": {
                    "Version": "2012-10-17",
                    "Statement": [
                        {
                            "Effect": "Allow",
                            "Principal": {"AWS": {"Fn::Sub": "arn:aws:iam::${AWS::AccountId}:root"}},
                            "Action": ["sts:AssumeRole"],
                        }
                    ],
                },
                "Path": "/",
                "Policies": [
                    {
                        "PolicyName": "root",
                        "PolicyDocument": {
                            "Version": "2012-10-17",
                            "Statement": [
                                {
                                    "Effect": "Allow",
                                    "Action": {"Ref": "StarParameter"},
                                    "Resource": {"Ref": "StarParameter"},
                                }
                            ],
                        },
                    }
                ],
            },
        }
    },
}

model = parse(template).resolve(extra_params={"AWS::AccountId": "123"})
rootRole = model.Resources["rootRole"]
policy = rootRole.Properties.Policies[0]
statement = policy.PolicyDocument.Statement[0]

assert statement.Action == "*"
assert statement.Resource == "*"
assert rootRole.Properties.AssumeRolePolicyDocument.Statement[0].Principal == {"AWS": "arn:aws:iam::123:root"}

Local Development Commands

This project uses uv for dependency management.

make install-dev    # Install all development dependencies
make coverage       # Run tests with coverage
make test           # Run linting and tests
make lock           # Update uv.lock file
make lock-upgrade   # Upgrade all dependencies and update uv.lock

Updating CloudFormation Actions

If the test tests/test_constants.py::test_cloudformation_actions is failing, it can be resolved by updating the known AWS Actions:

make install-cloudformation-update
make cloudformation-update

Metadata

Release files for pycfmodel 2.1.3

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for pycfmodel 2.1.3
File	Size	Uploaded
pycfmodel-2.1.3.tar.gz	308.3 kB	Sep 29, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for pycfmodel 2.1.3
File	Interpreter	ABI	Platform	Reset
pycfmodel-2.1.3-py3-none-any.whl 196.2 kB Sep 29, 2026	Python 3	none	any	Details

Total release size: 504.6 kB

Release files / pycfmodel-2.1.3.tar.gz

Download URL	pycfmodel-2.1.3.tar.gz
Size	308.3 kB
Tags	Source
SHA-256 checksum How to use checksums	`f73817033b6b7ce8d0ce29d9c1dd2cea0130836348818fe353c21cf986f8273c`
BLAKE2b-256 checksum How to use checksums	`30fdffe084171d58fa3e2f077cdf2a52402a7d7bb54c0ae4ea8be7b6f3b13faf`
Upload date	Sep 29, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.13.14`

Release files / pycfmodel-2.1.3-py3-none-any.whl

Download URL	pycfmodel-2.1.3-py3-none-any.whl
Size	196.2 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`6a2fa348b6ef3fb201c0218734f962bcc54c6b0ea82d150243c6f4037bcd1540`
BLAKE2b-256 checksum How to use checksums	`74a9c4ba25613d04844a75f75a3a2310c6dc26b7495405f6dcf5e08027287b75`
Upload date	Sep 29, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.13.14`