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Python Code Samples

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

2 matches
Data pipelines & processing medium

How to Find Missing Values in Large Datasets in Python

Analyze missing values across multiple large pandas DataFrames with counts and percentages.

pandas missing-data data-cleaning
Python
import pandas as pd
import numpy as np

def find_missing_values_summary(datasets):
    """Analyze missing values across multiple datasets (dict of name: DataFrame)."""
    summary = {}
    for name, df in datasets.items():
        missing_count = df.isnull().sum()
        total_rows = len(df)
        missing_pct = (mi…
41 0 Open
Database scaling & optimization medium

Approximate Count with HyperLogLog in Python

A mock HyperLogLog implementation uses hash-based registers to estimate cardinality of large datasets with sublinear memory.

hyperloglog cardinality hash
Python
import hashlib

class HyperLogLog:
    def __init__(self, precision=4):
        if precision < 4 or precision > 16:
            raise ValueError("precision must be between 4 and 16")
        self.precision = precision
        self.registers = [0] * (1 << precision)

    def _hash(self, value):
        return int(hashl…
14 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.