Python Code
Samples
Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Create a Mock STS AssumeRole Credentials Dict in Python
Build a realistic AWS STS AssumeRole response dict with temporary credentials, expiry time, and assumed role ARN for local testing.
import json
from datetime import datetime, timedelta, timezone
def mock_sts_credentials(role_arn, session_name, duration=3600):
now = datetime.now(timezone.utc)
expiration = now + timedelta(seconds=duration)
credentials = {
"Credentials": {
"AccessKeyId": "ASIAEXAMPLEACCESSKEY",
…How to Mock RDS Snapshot Create and Restore in Python
Mock AWS RDS snapshot creation and restore operations in Python tests using moto and boto3 without hitting real AWS services.
import boto3
from moto import mock_rds
@mock_rds
def create_and_restore_snapshot():
client = boto3.client("rds", region_name="us-east-1")
client.create_db_instance(
DBInstanceIdentifier="my-db",
DBInstanceClass="db.t3.micro",
Engine="postgres",
AllocatedStorage=20,
Mas…How to Validate AWS Security Group Ingress Rules in Python
Validates AWS security group ingress rules (protocol, port ranges, CIDR, description) and returns a list of errors or OK.
from dataclasses import dataclass
from typing import List, Optional
@dataclass
class SecurityGroupRule:
protocol: str
port_range: tuple
cidr: str
description: str = ""
def validate_ingress_rule(rule: SecurityGroupRule) -> List[str]:
"""Validate a security group ingress rule against common AWS pat…How to mock EC2 describe-instances tag filtering in Python
Simulate AWS EC2 describe-instances with tag-based filtering using a mock dataset and conditional list comprehension.
import json
from datetime import datetime, timezone
def mock_describe_instances(tag_key: str, tag_value: str) -> list[dict]:
"""Simulate EC2 describe-instances with tag filtering."""
all_instances = [
{"InstanceId": "i-0abc123", "State": "running", "Tags": [{"Key": "Name", "Value": "web-server"}, {"K…How to mock boto3 S3 upload file wrapper in Python
Wrap an S3 put_object call in a testable function that returns metadata, and mock boto3 to verify the upload without touching AWS.
import boto3
import io
def upload_file_to_s3(file_obj, bucket, key, object_metadata=None):
"""Upload a file-like object to S3 and return a metadata dict."""
s3 = boto3.client("s3")
content = file_obj.read()
s3.put_object(
Bucket=bucket,
Key=key,
Body=content,
Metadata=…How to mock boto3 S3 upload in Python
Shows how to mock the boto3 S3 client with unit tests and wrap an upload function to return a dictionary with status details.
import boto3
from unittest.mock import Mock, patch
class S3Uploader:
def __init__(self, bucket_name):
self.bucket_name = bucket_name
self.s3 = boto3.client("s3", region_name="us-east-1")
def upload_file(self, local_path, s3_key):
self.s3.upload_file(local_path, self.bucket_name, s3_ke…Mock CloudWatch put_metric_data in Python
Simulate AWS CloudWatch put_metric_data with validation and formatted output for local testing without AWS.
import json
from datetime import datetime, timezone
def put_metric_data(namespace, metric_data_list):
"""
Mock AWS CloudWatch put_metric_data.
Validates and prints the metrics that would be sent.
"""
timestamp = datetime.now(timezone.utc).isoformat()
print(f"[MockCloudWatch] Received request …Mock Route53 change_resource_record_sets in Python
This code demonstrates how to mock AWS Route53 change_resource_record_sets API calls using the botocore Stubber, allowing you to test DNS update logic without touching real infrastructure.
import boto3
from botocore.exceptions import ClientError
def mock_change_resource_record_sets():
"""Demonstrates Route53 change_resource_record_sets with a mock client."""
# Create a mock Route53 client
route53 = boto3.client('route53', region_name='us-east-1',
aws_access_key_id…Mock S3 List Objects Paginator in Python
This code implements a mock S3 paginator that yields pages of object keys, mimicking the behavior of boto3's list_objects_v2 paginator for local testing.
import json
from datetime import datetime, timezone
class MockS3Paginator:
"""A mock S3 list_objects_v2 paginator returning pages of keys."""
def __init__(self, bucket, all_keys, page_size=1000):
self.bucket = bucket
self.all_keys = all_keys
self.page_size = page_size
def pagina…How to mock S3 remote backend for Terraform in Python
Simulate a Terraform S3 remote backend using moto to write and read state files, enabling local testing without real AWS.
import boto3
from moto import mock_aws
import json
from pathlib import Path
@mock_aws
def demo_s3_remote_backend():
s3 = boto3.client("s3", region_name="us-east-1")
bucket = "terraform-state-bucket"
key = "env/prod/terraform.tfstate"
s3.create_bucket(Bucket=bucket)
# Simulate Terraform w…Browse by section
Each section groups closely related Python snippets.
Guide: free Python code samples library
Copy-ready Python snippets for learners and developers
PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.
How to use this library
- Pick a topic section — strings, lists, files, functions, and more
- Open a sample, read How it works, and copy the code block
- Run it in the IDE, tweak values, then take a related quiz or tutorial lesson
Samples vs tutorials and challenges
Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.