What's the difference between Python's threading and multiprocessing modules?
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!
1 Answer
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 10002. 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 result3. 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)Comments
alex_dev: Have you considered using Django's async views for this use case? Might be more efficient for I/O operations. 2 months ago
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