It is a guard against a stack overflow, yes. Python (or rather, the CPython implementation) doesn’t optimize tail recursion, and unbridled recursion causes stack overflows. You can check the recursion limit with sys.getrecursionlimit: import sys print(sys.getrecursionlimit()) and change the recursion limit with sys.setrecursionlimit: sys.setrecursionlimit(1500) but doing so is dangerous — the standard limit is a … Read more
The recursion limit is not the limit on recursion but the maximum depth of the python interpreter stack.There is something on the stack before your function gets executed. Spyder executes some python stuff before it calls your script, as do other interpreters like ipython. You can inspect the stack via methods in the inspect module. … Read more
No matter what you do, you are going to have to unwind the stack. This leaves two options: Magic return value (as described by one of the Toms) Throw an exception (as mentioned by thaggie) If the case where you want things to die is rare, this may be one of those situations where throwing … Read more
You are facing this issue because the Statemaster model contains the object of Districtmaster model, which itself contains the object of Statemaster model. This causes an infinite json recursion. You can solve this issue by 3 methods. 1 – Create a DTO and include only the fields that you want to display in the response. … Read more
The problem lies in your base case. “The height of a tree is the length of the path from the root to the deepest node in the tree. A (rooted) tree with only a node (the root) has a height of zero.” – Wikipedia If there is no node, you want to return -1 not … Read more
If you want to extract the files to the respective folder you can try this find . -name “*.zip” | while read filename; do unzip -o -d “`dirname “$filename”`” “$filename”; done; A multi-processed version for systems that can handle high I/O: find . -name “*.zip” | xargs -P 5 -I fileName sh -c ‘unzip -o … Read more
I played around with domi27’s idea and came up with this. I made a nested array as my tree, [‘link’][‘sublinks’] is null or another array of more of the same. Templates The sub-template file to recurse with: <!–includes/menu-links.html–> {% for link in links %} <li> <a href=”https://stackoverflow.com/questions/8326482/{{ link.href }}”>{{ link.name }}</a> {% if link.sublinks %} … Read more
Let’s look at a simple recursive function that expresses our program at a high level let RUNNING = true const main = async (elem, color = Color ()) => RUNNING ? delay (color, FPS) .then (effect (color => setElemColor (elem, color))) .then (color => main (elem, stepColor (color))) : color We’ve done a little wishful … Read more
python allows you to attach a variable (catalan.counter in the snippet below) to the function object, so you don’t have to pass the counter along all the time and don’t need a global variable: def catalan(n): catalan.counter += 1 if n <= 1: return 1 res = 0 for i in range(n): res += catalan(i) … Read more
First of all map the objects onto a new hash (array) in which the index is the id: // map the array onto hash $hash = array(); foreach($array as $object) { $hash[$object->id] = array(‘object’ => $object); } Then transpose this flat hash into a tree-like structure, see this answer for another code example, it’s merely … Read more