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Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

62 matches
Big data & Spark easy

How to Mock Hive Support in PySpark with unittest.mock

This code demonstrates how to mock Hive support in a PySpark environment using unittest.mock to simulate SQL queries returning fixed data.

pyspark hive mock
Python
from unittest.mock import Mock, patch


def get_hive_tables(spark):
    """Mock Hive support by returning a fixed list of tables."""
    return spark.sql("SHOW TABLES").collect()


class HiveTable:
    """Simple class that mimics a Hive table row."""
    def __init__(self, database, tableName):
        self.database =…
14 0 Open
Big data & Spark medium

How to Mock a Compute-Collect Action Trigger in Python

Mock a compute-collect action trigger using Python's unittest.mock to simulate Spark-style job execution and assert trigger behavior.

testing mock spark
Python
Here's a Python code sample for the problem title "Action trigger compute collect mock":
14 0 Open
ML engineering pipelines easy

How to Mock MLflow log_params and log_metrics in Python

Use unittest.mock to patch MLflow's log_param and log_metric, run the training function, and verify logging calls without touching a real tracking server.

mlflow mock testing
Python
from unittest.mock import Mock, patch
import mlflow


def train_model():
    mlflow.log_param("learning_rate", 0.01)
    mlflow.log_param("epochs", 10)
    mlflow.log_metric("accuracy", 0.95)
    mlflow.log_metric("loss", 0.05)
    return "Training completed"


if __name__ == "__main__":
    with patch("mlflow.log_par…
15 0 Open
A/B testing & experimentation easy

How to Create a Sticky Consistent Mock with unittest.mock in Python

Shows how to use unittest.mock.patch.object to mock a method consistently across multiple calls, returning a sticky value every time.

unittest mock testing
Python
from unittest.mock import patch

class Database:
    def fetch(self, key):
        return f"real value for {key}"

def get_value(db, key):
    return db.fetch(key)

if __name__ == "__main__":
    db = Database()
    with patch.object(db, "fetch", return_value="sticky value") as mock_fetch:
        result1 = get_value(…
15 0 Open
A/B testing & experimentation medium

How to Mock Sequential Calls in Python with unittest.mock

Use Mock.side_effect to return a different result for each sequential call and verify the call order with assert_has_calls.

mock unittest testing
Python
import unittest
from unittest.mock import Mock

class Service:
    def fetch(self, item_id):
        raise NotImplementedError

def process_items(service, ids):
    results = []
    for item_id in ids:
        result = service.fetch(item_id)
        results.append(result)
    return results

if __name__ == "__main__":…
14 0 Open
A/B testing & experimentation medium

How to Mock Time for Cache TTL Testing in Python

This code demonstrates how to test a cache's TTL expiration logic by mocking time.time with unittest.mock to control the passage of time.

caching ttl unit-testing
Python
import time
from unittest.mock import patch

class ConfigCache:
    def __init__(self, ttl=60):
        self.ttl = ttl
        self._store = {}
        self._timestamps = {}

    def get(self, key):
        if key not in self._store:
            return None
        if time.time() - self._timestamps[key] > self.ttl:
  …
17 0 Open
Database scaling & optimization easy

How to Mock a Function Call in Python with unittest.mock

Use unittest.mock.Mock to wrap a function and spy on its call count and arguments in Python.

mock unittest spy
Python
import random
from unittest.mock import Mock, patch


def select_n_plus_one(numbers: list[int]) -> int:
    """Return the first number that appears more than once, if any."""
    seen = set()
    for num in numbers:
        if num in seen:
            return num
        seen.add(num)
    return -1


def detect_mock(se…
14 0 Open
Auth & security at scale medium

How to Mock Environment Variables in Python for 12-Factor Config

Read 12-factor config from env vars and test/mock them with unittest.mock.patch.dict without touching the real environment.

environment-variables 12-factor testing
Python
import os
import json
from unittest.mock import patch

def load_config(env_prefix="APP"):
    """Read 12-factor style config from env vars"""
    required = ["DATABASE_URL", "API_KEY"]
    optional = {"PORT": "8080", "DEBUG": "false"}
    
    config = {}
    for key in required:
        full_key = f"{env_prefix}_{key…
13 0 Open
Auth & security at scale medium

How to Mock HTTP Responses to Verify HSTS Headers in Python

This code demonstrates how to use unittest.mock to intercept and capture HTTP response headers, specifically the Strict-Transport-Security header, from a mocked HTTPServer handler for security validation.

hsts mock security
Python
from http.server import BaseHTTPRequestHandler, HTTPServer
from unittest.mock import patch

class StrictTransportMock(BaseHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header("Strict-Transport-Security", "max-age=31536000; includeSubDomains")
        self.end_headers()
  …
13 0 Open
Production deployment patterns medium

How to Mock Kubernetes Secret Mounts in Python

Create and inspect a mock Kubernetes secret volume mount using the official client library and unittest.mock.

kubernetes mock testing
Python
import json
from kubernetes import client, config, watch
from unittest.mock import Mock, patch

def create_mock_mount_spec():
    """Create a mock Kubernetes secret volume mount."""
    mock_client = Mock()
    mock_client.api_version = "v1"
    mock_client.kind = "Secret"
    mock_client.metadata = {"name": "my-secre…
14 0 Open
Production deployment patterns easy

How to Mock a Dependency for Readiness Probe in Python

Use unittest.mock.Mock to simulate a dependency's readiness check response for testing a service's is_ready method without hitting a real connection.

unittest.mock mock readiness probe
Python
import time
import unittest
from unittest.mock import Mock

class Service:
    def __init__(self, dependency):
        self.dependency = dependency

    def is_ready(self):
        try:
            result = self.dependency.check()
            return result == "ready"
        except Exception:
            return False
…
17 0 Open
Production deployment patterns easy

How to Mock a Slow Startup Probe for Fast Testing in Python

This code shows how to replace a slow startup probe's initialization with a mock to make tests run fast and reliably.

mock testing startup-probe
Python
import time
from unittest.mock import Mock, patch


class StartupProbe:
    def __init__(self, init_time):
        self.init_time = init_time
        self.ready = False

    def initialize(self):
        time.sleep(self.init_time)
        self.ready = True
        return self.ready


def run_startup_probe(probe):
    …
15 0 Open
Production deployment patterns easy

How to Mock time.sleep in a Python PreStop Hook

This code simulates a Kubernetes PreStop hook that delays shutdown, then mocks time.sleep to verify the hook logic without real delay.

mocking prestop kubernetes
Python
import subprocess
import sys
import time
from unittest.mock import patch

def pre_stop_hook():
    """Simulate a Kubernetes PreStop hook that sleeps before shutdown."""
    print("PreStop hook started: delaying shutdown")
    time.sleep(3)
    print("PreStop hook completed: ready to shutdown")

if __name__ == "__main_…
14 0 Open
Production deployment patterns medium

How to Smoke Test a Deployment in Python with unittest.mock

Run a post-deploy smoke test by mocking the deployment status check to verify your health-check logic returns PASS/FAIL.

deployment smoke-test unittest-mock
Python
import unittest
from unittest.mock import Mock, patch

class DeploymentService:
    def check_status(self):
        return "unknown"

def smoke_test_deploy():
    service = DeploymentService()
    with patch.object(service, "check_status", return_value="healthy") as mock_check:
        status = service.check_status()
…
13 0 Open

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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.