Reference library

Comprehensions & generators

List/dict/set comprehensions, generator expressions, and lazy iteration.

3 matches

Generate UUID4 Values with a Python Generator

This code defines a generator function that yields mock UUID4 values, allowing you to stream unique identifiers one at a time.

uuid generators streaming

Python

import uuid

def generate_uuids(count=5):
    """Generate a stream of mock UUID4 values."""
    for _ in range(count):
        yield uuid.uuid4()

if __name__ == "__main__":
    # Generate and print 5 UUIDs
    for uid in generate_uuids(5):
        print(uid)

15 0 Open

Comprehensions & generators medium

How to stream parse JSON arrays in Python

This code demonstrates two generators: one that streams a JSON array as individual chunks, and another that incrementally parses those chunks into Python objects using json.JSONDecoder.

json generator streaming

Python

import json


def json_array_stream(items):
    """Generator that yields JSON-encoded values one at a time."""
    yield "["
    for i, item in enumerate(items):
        if i > 0:
            yield ","
        yield json.dumps(item)
    yield "]"


def parse_json_stream(stream):
    """Consumes a stream of JSON fragme…

14 0 Open

Comprehensions & generators easy

Memory efficient map over large file in Python

A generator-based streaming map that processes a large file line by line without loading the whole file into memory.

generator file-io streaming

Python

import sys

def process_lines(file_path):
    """Memory-efficient map over a large file: yields processed lines."""
    with open(file_path, 'r') as f:
        for line in f:
            # Example mapping: strip whitespace and uppercase
            yield line.strip().upper()

if __name__ == "__main__":
    # Use a sma…

12 0 Open

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