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Python Code Samples

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

4 matches
Big data & Spark medium

Bloom Filter Join Mock in Python

A mock hash join that uses a Bloom filter to pre-filter one table before performing an exact match, reducing the number of comparisons in large dataset joins.

bloom filter join hashing
Python
import hashlib
import random
import string


class BloomFilter:
    def __init__(self, size: int = 200, num_hashes: int = 3):
        self.bits = [False] * size
        self.size = size
        self.num_hashes = num_hashes

    def _hashes(self, item: str):
        result = []
        for seed in range(self.num_hashes…
12 0 Open
Big data & Spark easy

How to Mock a Hash Join on Large and Small Tables in Python

This code efficiently joins a large dataset (1000 rows) with a small lookup table (20 rows) by building a dictionary hash lookup, mimicking a hash join strategy used in big data systems.

hash-join dictionaries data-join
Python
import random
from pprint import pprint

# Large table: 1000 rows (id, group_id, value)
large = [{"id": i, "group_id": random.randint(1, 20), "value": random.random() * 100} for i in range(1000)]

# Small table: 20 rows (group_id, label)
small = [{"group_id": g, "label": f"Group-{g}"} for g in range(1, 21)]

# Mock a …
12 0 Open
Big data & Spark medium

Mock Predicate Pushdown in Python for Big Data Queries

Simulate predicate pushdown by applying filters at the storage layer before materializing rows, showing how big data engines optimize queries.

big-data query-optimization predicate-pushdown
Python
class Query:
    def __init__(self, table, rows):
        self.table = table
        self.rows = rows

    def filter(self, predicate):
        return Query(
            self.table,
            [row for row in self.rows if all(predicate(row) for predicate in predicate)]
        )

    def filter_pushdown(self, predica…
14 0 Open
Big data & Spark medium

Skew Join Salting Key in Python (Demo)

Demonstrates skew join salting by expanding a smaller side with salt keys and matching rows on the larger side via random salt assignment.

skew join salting distributed
Python
import random


def skew_join_salting_key(left_df, right_df, salt_range=4):
    """
    Demonstrates skew join salting: expand the smaller side with salt keys,
    then attach a salt key to each row on the larger side.
    Returns a list of (left, right, salt) tuples.
    """
    skewed_left = []
    for row in left_d…
13 0 Open

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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.

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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.