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Python Code Samples

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162 matches
Big data & Spark easy

Compaction Small Files Mock in Python

Simulates a small-files compaction job by creating small mock files and merging them into a single output file using Python's standard library.

compaction file-io mock
Python
from pathlib import Path
import tempfile
import os


def create_small_files(directory: Path, file_count: int = 5, lines_per_file: int = 3):
    """Create several small mock files with sample content."""
    directory.mkdir(exist_ok=True)
    for i in range(file_count):
        file_path = directory / f"part-{i:04d}.tx…
18 0 Open
Big data & Spark easy

How to Broadcast a Small Lookup Table in Python

Simulates broadcasting a small lookup table by iterating key-value pairs and emitting packed rows to subscribers with deterministic output.

broadcast lookup-table dictionary
Python
import random

# Generate a deterministic mock broadcast of a small lookup table
# with 5 keys and random integer values (seeded for reproducibility)

data = {
    "sensor_a": 22,
    "sensor_b": 87,
    "sensor_c": 43,
    "sensor_d": 65,
    "sensor_e": 31,
}

# Simulate a broadcast to subscribers by iterating and p…
16 0 Open
Big data & Spark easy

Sliding Window Streaming Mock in Python

A simple Python class that maintains a sliding window of recent streaming values and computes the running average.

streaming sliding-window averages
Python
import time
import random

class StreamingMock:
    """Produces a stream of numbers using a sliding window."""
    
    def __init__(self, window_size=5):
        self.window = []
        self.window_size = window_size
        
    def push(self, value):
        """Add a value, sliding the window forward."""
        s…
13 0 Open
ML engineering pipelines easy

How to Compute a Confusion Matrix in Python

Compute a multi-class confusion matrix from true and predicted labels using pure Python dictionaries and nested lists, then format it for readable output.

confusion-matrix classification ml-metrics
Python
from collections import defaultdict

def compute_confusion_matrix(y_true, y_pred, labels):
    """Compute confusion matrix using Python dicts and nested lists."""
    label_index = {label: i for i, label in enumerate(labels)}
    matrix = [[0] * len(labels) for _ in range(len(labels))]
    
    for true, pred in zip(y…
15 0 Open
ML engineering pipelines easy

How to Define Dagster ML Assets in Python

Define a chain of Dagster software-defined assets that compute raw features, normalized features, and predictions for an ML pipeline.

dagster ml-pipeline asset
Python
from dagster import asset


@asset
def raw_features():
    return {"sepal_length": [5.1, 4.9, 6.2], "sepal_width": [3.5, 3.0, 3.4]}


@asset
def normalized_features(raw_features):
    values = raw_features["sepal_length"]
    mean = sum(values) / len(values)
    std = (sum((x - mean) ** 2 for x in values) / len(values…
14 0 Open
ML engineering pipelines easy

How to Evaluate Accuracy, Precision, and Recall in Python

Compute accuracy, precision, and recall for a binary classification model using scikit-learn's metrics functions.

metrics classification scikit-learn
Python
from sklearn.metrics import accuracy_score, precision_score, recall_score

if __name__ == "__main__":
    y_true = [0, 1, 1, 0, 1, 0, 1, 1]
    y_pred = [0, 1, 0, 0, 1, 0, 1, 1]

    accuracy = accuracy_score(y_true, y_pred)
    precision = precision_score(y_true, y_pred)
    recall = recall_score(y_true, y_pred)

   …
14 0 Open
ML engineering pipelines easy

How to Impute Missing Values with Mean in Python

Replace None values in a list with the mean of the existing values using Python's statistics module.

imputation missing-data statistics
Python
import statistics
from statistics import mean


def impute_mean(values):
    """Replace None with the mean of the non-None values."""
    # Filter out None to compute the mean of existing values
    valid = [v for v in values if v is not None]
    if not valid:
        return values  # nothing to impute if all are Non…
15 0 Open
ML engineering pipelines easy

How to Mock Shadow Mode Inference in Python

Simulates running multiple candidate models in shadow mode by adding randomized delays and returning their outputs alongside a primary model's output.

ml-pipeline shadow-mode simulation
Python
import random
import time


def shadow_mode_inference(candidates, mock_delay=0.1):
    """
    Simulates running multiple candidate models in 'shadow mode'
    by adding tiny randomized delays and returning their outputs
    alongside the primary model's output.
    """
    primary_output = "primary: answer"
    shado…
14 0 Open
A/B testing & experimentation easy

Difference in Differences Mock in Python

Generate mock panel data with a known treatment effect and compute a difference-in-differences estimate using group and period means.

did pandas simulation
Python
import numpy as np
import pandas as pd

# Generate mock panel data: 2 groups (control=0, treatment=1) × 2 periods (pre=0, post=1)
rng = np.random.default_rng(42)
n_per_cell = 50

data = []
for group in [0, 1]:
    for period in [0, 1]:
        # True effect: treatment increases outcome by 5 in the post period
        …
17 0 Open
A/B testing & experimentation easy

Generate a Mock Multi-Armed Bandit Report in Python

Simulate a multi-armed bandit experiment with random pulls and rewards, then output a JSON report with per-arm statistics.

bandit simulation random
Python
import random
import json

def generate_mock_bandit_report(num_arms=5, num_rounds=100, seed=42):
    random.seed(seed)
    arms = ["A", "B", "C", "D", "E"][:num_arms]
    true_means = {arm: random.uniform(0.3, 0.7) for arm in arms}
    pulls = {arm: 0 for arm in arms}
    rewards = {arm: 0 for arm in arms}

    for _ …
17 0 Open
A/B testing & experimentation easy

How to Calculate Minimum Sample Size for a T-Test in Python

Compute the minimum sample size per group for a two-sample t-test using effect size, significance level, and statistical power.

sample-size statistics ab-testing
Python
import math
from scipy.stats import norm


def min_sample_size(effect_size, alpha=0.05, power=0.8):
    """
    Calculate minimum sample size for a two-sample t-test (equal groups).

    Args:
        effect_size: Cohen's d (standardized mean difference)
        alpha: significance level (Type I error)
        power: …
16 0 Open
A/B testing & experimentation easy

How to Calculate Secondary Metrics in Python

Computes distribution, variability, and spread of a numeric dataset using Python's statistics and collections modules.

statistics data-analysis metrics
Python
import random
import statistics
from collections import Counter

def explore_secondary_metrics(data):
    """Calculate secondary metrics: distribution, variability, and spread."""
    if not data:
        return "No data provided"
    
    total = sum(data)
    mean = statistics.mean(data)
    median = statistics.medi…
17 0 Open
A/B testing & experimentation easy

How to Calculate Weighted Grades and Generate Mock Notes in Python

Compute a weighted physics grade from exam and homework scores, then generate a performance-based mock note with percentage and feedback.

grades weighted-average mock-note
Python
def get_physics_grade(exam_score, homework_score):
    """Calculate final grade from exam and homework scores."""
    exam_weight = 0.7
    homework_weight = 0.3
    return (exam_score * exam_weight) + (homework_score * homework_weight)


def mock_note(correct_score, max_score, student_name):
    """Generate a mock no…
11 0 Open
A/B testing & experimentation easy

How to Mock a Confidence Interval for a Proportion in Python

Simulate a Bernoulli sample and compute a 95% confidence interval for a proportion using the normal approximation in Python.

confidence-interval simulation statistics
Python
import random
import math

def mock_ci(n=100, p_true=0.5, z=1.96, seed=42):
    """Simulate a sample proportion and compute its 95% confidence interval."""
    random.seed(seed)
    successes = sum(1 for _ in range(n) if random.random() < p_true)
    p_hat = successes / n
    se = math.sqrt(p_hat * (1 - p_hat) / n)
  …
16 0 Open
Database scaling & optimization easy

How to Validate Data Before Scaling in Python

A reusable Python helper that validates required fields and constraint checks on data rows before entering a database pipeline, improving data quality and throughput.

validation data-quality scaling
Python
def validate_data(data, required_fields, constraints=None):
    """
    Basic validation helper demonstrating data-quality workflows
    before scaling (catches bad rows early, improves throughput).
    """
    constraints = constraints or {}

    errors = []
    for field in required_fields:
        if field not in d…
16 0 Open
Production deployment patterns easy

How to Mock a GitHub Actions Workflow in Python

Build a dataclass-based model of a GitHub Actions workflow and simulate its execution to validate steps and outputs before deployment.

github-actions dataclasses mock
Python
import json
from dataclasses import dataclass, asdict
from typing import List, Dict, Any


@dataclass
class Step:
    name: str
    run: str


@dataclass
class Job:
    name: str
    steps: List[Step]
    runs_on: str = "ubuntu-latest"


@dataclass
class Workflow:
    name: str
    jobs: List[Job]

    def to_github_a…
14 0 Open
Production deployment patterns easy

How to build a maintenance mode page in Python

Mock a service maintenance status page that computes remaining downtime and lists affected features from a simple class.

maintenance status datetime
Python
from datetime import datetime

class MaintenanceMode:
    """Mock a maintenance mode status page for a service."""
    
    def __init__(self, service_name: str, scheduled_end: str):
        self.service_name = service_name
        self.scheduled_end = datetime.fromisoformat(scheduled_end)
        self.affected_featur…
14 0 Open
Production deployment patterns easy

How to simulate GitLab CI stages in Python

Build a lightweight Python mock of GitLab CI pipeline stages to test job sequencing and output locally.

gitlab ci simulation
Python
def mock_gitlab_ci_stages():
    stages = ["build", "test", "deploy"]
    stage_status = {}

    for stage in stages:
        jobs = []

        if stage == "build":
            jobs = ["compile", "package"]
        elif stage == "test":
            jobs = ["unit", "integration", "e2e"]
        elif stage == "deploy":…
15 0 Open

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