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Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

33 matches
Database scaling & optimization medium

How to Build a Shard Map Mock Dict in Python

Implement a dictionary-like class that distributes keys across multiple shards using Python's hash() for realistic data partitioning.

dict sharding hash
Python
class ShardMap:
    def __init__(self, shard_count):
        self.shards = {i: {} for i in range(shard_count)}
        self.shard_count = shard_count

    def _shard_for(self, key):
        return hash(key) % self.shard_count

    def __getitem__(self, key):
        return self.shards[self._shard_for(key)][key]

    d…
14 0 Open
Database scaling & optimization medium

How to Implement Consistent Hashing in Python

Build a consistent hash ring in Python that distributes keys across nodes and minimizes remapping when nodes are added or removed.

consistent-hashing distributed-systems sharding
Python
import hashlib
from bisect import bisect_right


class ConsistentHashRing:
    def __init__(self, nodes, replicas=3):
        self.replicas = replicas
        self.ring = {}
        self.sorted_keys = []
        for node in nodes:
            self.add_node(node)

    def _hash(self, key):
        return int(hashlib.md…
15 0 Open
Auth & security at scale medium

How to Create and Verify HMAC SHA256 API Signatures in Python

Generate and verify HMAC-SHA256 signatures for API requests using Python's hmac, hashlib, and base64 modules.

hmac sha256 authentication
Python
import hmac
import hashlib
import base64
import json
from datetime import datetime, timezone

def create_api_signature(secret_key: str, method: str, path: str, timestamp: str, body: dict = None) -> str:
    """Create HMAC-SHA256 signature for API request."""
    payload = {
        "method": method.upper(),
        "p…
14 0 Open
Auth & security at scale medium

How to Hash Passwords and Authenticate Users in Python

A beginner-friendly dataclass-based design that hashes passwords with PBKDF2 and verifies them securely using constant-time comparisons.

security password hashing pbkdf2
Python
import hashlib
import hmac
import secrets
from dataclasses import dataclass
from typing import Optional


@dataclass
class User:
    id: int
    username: str
    password_hash: str
    salt: str


def hash_password(password: str) -> tuple[str, str]:
    salt = secrets.token_hex(16)
    password_hash = hashlib.pbkdf2_…
16 0 Open
Auth & security at scale medium

How to Implement a Vault Dynamic Database Credentials Mock in Python

A Python dataclass-based mock of HashiCorp Vault that issues short-lived database credentials, tracks leases, and revokes them, demonstrating dynamic secrets rotation.

vault secrets database
Python
import time
import json
from dataclasses import dataclass, field
from typing import Dict


@dataclass
class DynamicCredential:
    username: str
    password: str
    lease_duration: int
    created_at: float = field(default_factory=time.time)

    def is_valid(self) -> bool:
        return time.time() - self.created_…
16 0 Open
Auth & security at scale medium

How to Mock Certificate Pinning with SPKI Hash in Python

Shows how to compute and compare a certificate's SubjectPublicKeyInfo SHA-256 hash for pinning validation in Python.

certificate ssl pinning
Python
import hashlib
import base64
import ssl
import socket

class MockCertificatePinner:
    """Demonstrates SPKI hash pinning for certificate validation."""
    
    def __init__(self, pinned_spki_hashes):
        self.pinned_hashes = set(pinned_spki_hashes)
    
    def get_spki_hash(self, cert_pem):
        """Compute t…
14 0 Open
Auth & security at scale medium

How to Tune scrypt Parameters in Python

Adjust scrypt work factor (N) to hit a target hashing time with a mock benchmark loop, then return tunable parameters and a derived key.

scrypt hashing password-security
Python
import hashlib

def tune_scrypt_params(target_time=0.1, base_n=2**14, base_r=8, base_p=1):
    """Mock tuning of scrypt params based on target time."""
    n, r, p = base_n, base_r, base_p
    iterations = 0
    
    for _ in range(5):  # simple mock adjustment loop
        iterations += 1
        mock_time = 0.05 + (…
14 0 Open
Auth & security at scale medium

How to mock Argon2 password hashing in Python

This code demonstrates a mock Argon2 password hasher using HMAC-SHA256 iterations, providing hash and verify methods that mimic Argon2's salted, iterated derivation.

password-hashing security argon2
Python
import hashlib
import hmac
import os


class Argon2Mock:
    def __init__(self, salt_size=16, hash_len=32):
        self.salt_size = salt_size
        self.hash_len = hash_len
        
    def hash(self, password: str, salt: bytes = None) -> str:
        if salt is None:
            salt = os.urandom(self.salt_size)
 …
14 0 Open
Production deployment patterns medium

How to Mock Canary Deployment Traffic Split in Python

Simulate a canary deployment's stable/canary traffic split using deterministic request hashing to mock rollout behavior with precise percentage control.

canary-deployment traffic-split simulation
Python
class CanaryDeployment:
    def __init__(self, stable_weight: float = 0.9, canary_weight: float = 0.1):
        self.stable_weight = stable_weight
        self.canary_weight = canary_weight
        self.total_weight = stable_weight + canary_weight

    def route_request(self, request_id: int) -> str:
        """Route …
14 0 Open

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