What's the difference between Python's threading and multiprocessing modules?

Answered
Aug 30, 2025 892 views 1 answers
40

I'm working on a Python application and running into an issue with Python performance. Here's the problematic code:


# Current implementation
def fibonacci(n):
    if n <= 1:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

# This causes RecursionError for large n
result = fibonacci(1000)

The error message I'm getting is: "AttributeError: 'NoneType' object has no attribute 'get'"

What I've tried so far:

  • Used pdb debugger to step through the code
  • Added logging statements to trace execution
  • Checked Python documentation and PEPs
  • Tested with different Python versions
  • Reviewed similar issues on GitHub and Stack Overflow

Environment information:

  • Python version: 3.11.0
  • Operating system: Windows 11
  • Virtual environment: venv (activated)
  • Relevant packages: django, djangorestframework, celery, redis

Any insights or alternative approaches would be very helpful. Thanks!

D
Asked by david_web
Bronze 75 rep

1 Answer

20

The RecursionError occurs when Python's recursion limit is exceeded. Here are several solutions:

1. Increase recursion limit (temporary fix):

import sys
sys.setrecursionlimit(10000)  # Default is usually 1000

2. Convert to iterative approach (recommended):

# Recursive (problematic for large inputs)
def factorial_recursive(n):
    if n <= 1:
        return 1
    return n * factorial_recursive(n - 1)

# Iterative (better)
def factorial_iterative(n):
    result = 1
    for i in range(2, n + 1):
        result *= i
    return result

3. Use memoization for recursive algorithms:

from functools import lru_cache

@lru_cache(maxsize=None)
def fibonacci(n):
    if n < 2:
        return n
    return fibonacci(n-1) + fibonacci(n-2)

4. Tail recursion optimization (manual):

def factorial_tail_recursive(n, accumulator=1):
    if n <= 1:
        return accumulator
    return factorial_tail_recursive(n - 1, n * accumulator)
J
Answered by james_ml 1 week, 4 days ago
Bronze 90 rep

Comments

alex_dev: Have you considered using Django's async views for this use case? Might be more efficient for I/O operations. 1 week, 4 days ago

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