Segmentation Fault For Deep Recursion Upon Going From Python 2.6 To 2.7

I have simple recursive program to find connected subgraphs. The code works by traversing, from each unvisited vertex in the graph, all the edges (recursively) and marking those wh

Solution 1:

Because your Python uses C stack, it's overflowed. setrecursionlimit can't extend cstack size. it just make limit to raise exception before cstack overflows. Python's recursion has limited depth. Success in 2.6 is just lucky case.

You should change your code from recursion to iterative style or use stackless python(or PyPy). Read http://docs.python.org/2/library/sys.html#sys.setrecursionlimit

Solution 2:

You probably overflow stack with deep recursion somewhere in Python implementation. You may try changing stack dept with sys.setrecursionlimit

Another possibility is that you exhaust dynamic memory. Recursion is normally more taxing.

You had more luck with Python 2.6. Previous version required less memory for your algorithm.

Python isn't a functional language and doesn't optimise tail recursion. Rewriting the algorithm iteratively may be a better approach.