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Chunk Large File Upload Simulation by Blocks in Python
A Python script reads a large binary file in fixed-size chunks and simulates a block-by-block upload with per-chunk SHA256 hashing.
import os
import hashlib
from pathlib import Path
def read_file_in_chunks(file_path, chunk_size=8196):
"""Yield chunks of a file as bytes."""
with open(file_path, 'rb') as f:
while chunk := f.read(chunk_size):
yield chunk
def simulate_chunked_upload(file_path, chunk_size=8196):
"""S…Traverse Nested Dict Paths Depth-First in Python
Recursively walk a nested dictionary depth-first and yield each full path from root to leaf as lists.
def depth_first_paths(node, path=None):
if path is None:
path = []
if not isinstance(node, dict):
yield path + [node]
return
for key, value in node.items():
new_path = path + [key]
if isinstance(value, dict):
yield from depth_first_paths(value, …Build a Generator Pipeline in Python: Filter Then Map
Create a lazy data pipeline by chaining generator functions that read, filter, map, and write data step by step.
def read_data():
return ["a", "bb", "ccc", "dd", "eeeee", "f"]
def filter_short(words):
return (word for word in words if len(word) >= 2)
def map_to_upper(words):
return (word.upper() for word in words)
def write_data(words):
for word in words:
print(word)
if __name__ == "__main__":
…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.
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…How to Generate Primes with a Generator in Python
Generate prime numbers up to a limit using the Sieve of Eratosthenes wrapped in a generator expression for lazy evaluation.
def prime_generator(limit):
sieve = [True] * (limit + 1)
sieve[0] = sieve[1] = False
for i in range(2, int(limit ** 0.5) + 1):
if sieve[i]:
for j in range(i * i, limit + 1, i):
sieve[j] = False
return (num for num, is_prime in enumerate(sieve) if is_prime)
if __n…How to Send Values into a Python Generator Coroutine
Use the .send() method to pass values into a running generator coroutine and capture them.
def coroutine():
received = []
while True:
value = yield
received.append(value)
print(f"Coroutine received: {value}")
if value == "stop":
break
return received
if __name__ == "__main__":
gen = coroutine()
next(gen) # Prime the generator
gen.send("he…How to filter a generator with a predicate function in Python
This code defines a generator function that yields only items from an iterable that satisfy a given predicate, then tests it with even and positive number filters.
def filter_gen(predicate, iterable):
for item in iterable:
if predicate(item):
yield item
def is_even(num):
return num % 2 == 0
def is_positive(num):
return num > 0
if __name__ == "__main__":
numbers = range(-5, 10)
even_numbers = list(filter_gen(is_even, numbers))
p…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.
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…How to Stream Join Windowed Mock Topics in Python
Simulates two message topics and joins their events when timestamps fall within a sliding time window using Python generators and deques.
import itertools
import random
import time
from collections import deque
from dataclasses import dataclass, field
@dataclass
class Event:
key: str
value: int
timestamp: float = field(default_factory=time.time)
def generate_topic(prefix, keys, start_time):
while True:
yield Event(
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