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Python Code Samples

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

3 matches
Functions & basics medium

How to Implement a Trampoline for Tail Recursion in Python

This code implements a trampoline decorator that converts tail-recursive functions into iterative loops, allowing deep recursion without hitting Python's recursion limit.

trampoline tail-recursion decorator
Python 
def trampoline(fn):
    """Convert a tail-recursive function into an iterative loop."""
    def wrapper(*args, **kwargs):
        result = fn(*args, **kwargs)
        while callable(result):
            result = result()
        return result
    return wrapper

@trampoline
def factorial(n, acc=1):
    """Tail-recursi…
11 0 Open
Dictionaries & sets medium

Unflatten Dot Keys to Nested Dict in Python

Convert a flat dictionary with dot-separated keys into a nested dictionary structure using recursive setdefault loops.

dictionaries nested flatten
Python 
def unflatten_dot_keys(flat_dict):
    result = {}
    for flat_key, value in flat_dict.items():
        parts = flat_key.split(".")
        current = result
        for part in parts[:-1]:
            current = current.setdefault(part, {})
        current[parts[-1]] = value
    return result


if __name__ == "__main_…
14 0 Open
Concurrency & performance medium

How to Speed Up Downloads with ThreadPoolExecutor in Python

Compare sequential and thread-pool download loops to measure real speedup when I/O s bound.

threads concurrency performance
Python 
import time
import threading
from concurrent.futures import ThreadPoolExecutor

def download_file(file_id):
    """Simulate fetching a file by sleeping briefly."""
    time.sleep(0.2)  # pretend network latency
    return f"file_{file_id}"

def sequential_downloads(num_files):
    """Process files one at a time."""
  …
13 0 Open

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