Reference library

Comprehensions & generators

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

3 matches

How to Build a Backpressure Generator Pause Producer Demo in Python

Demonstrates a producer–consumer pattern with a fixed-size buffer that pauses production when full, simulating backpressure.

backpressure producer-consumer deque

Python

import time
import collections

def producer(buffer, max_size, items):
    """Adds items to the buffer until full, then pauses."""
    for item in items:
        while len(buffer) >= max_size:
            print(f"Buffer full ({len(buffer)}/{max_size}) — producer paused")
            time.sleep(0.1)
        buffer.appe…

14 0 Open

Comprehensions & generators medium

How to Throw an Exception into a Python Generator

This code demonstrates how to use the .throw() method on a generator to inject an exception at its current yield point and let it recover gracefully.

generator throw exception

Python

def demo_throw_into_generator():
    """Demonstrate throwing an exception into a running generator."""
    def counter():
        """Generator that counts until interrupted."""
        try:
            i = 0
            while True:
                yield i
                i += 1
        except ValueError as e:
        …

12 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

Browse by section

Each section groups closely related Python snippets.