Question

I’ve a part of my python program which is generated, the generated codes contains a lot of nested if / else, my problem is that a lot can be too much and I got this Error when running my code:

IndentationError: too many levels of indentation

I’ve read that this was some limitation defined on the low level of the python interpreter, does anybody know how I can find a workaround for it? Some interpreter parameters would be fine, the only solution proposal I’ve found suggests to recompile Python in order to set a different value for the MAXINDENT constant, which is not exactly what I’m dreaming of.

EDIT : The code is a big bunch of nested if...else , it’s dirty but it was the quickest I found to port a complex decision tree to Python. I know how dirty it is; I did not write it myself — I did not even plan to edit it (I would rather touch the generator).

I know I can modelize this decision tree in other fashions. What I would like is a way simpler than that, like tweaking the interpretor if possible.

EDIT 2 : Now I’ve done some refactoring, and my tree is stored as a dictionary: The loading of the file gives a new error :

s_push: parser stack overflow
MemoryError

Here again I found a resource suggesting some tweaks of the interpreter’s headers.

---

Answer 1

You can have deeply nested structures that are generated dynamically e.g., ~100 nested-levels list leads to s_push: parser stack overflow as a string literal but it works if you create it dynamically from json-text, example:

import ast
import json

N = 100
s = "["*N + "123" +"]"*N

L1 = json.loads(s)
def flatten(L):
    for el in L:
        try:
            for item in flatten(el):
                yield item
        except TypeError:
            yield el
assert next(flatten(L1)) == 123
print("json ok")

L2 = ast.literal_eval(s) # raises MemoryError