It is a normal situation.

If you see something like

I deleted it.

Then it means that your code exceeds the recursion limit.

How to solve:

Method 1

from sys import setrecursionlimit as R
R(10000)

At the start of your code, set the recursion limit

Method 2

from random import shuffle as r
from sys import setrecursionlimit as R
global L
L=100

def merge(l1,l2):
	global L
	R(L)
	L += 1
	if not (len(l1) and len(l2)):
		return l1+l2
	else:
		if l1[0]<l2[0]:
			return [l1[0]]+merge(l1[1:],l2[:])
		else:
			return [l2[0]]+merge(l1[:],l2[1:])

def sort(l):
	global L
	R(L)
	L+=1
	if len(l)<2:
		return l
	else:
		return merge(sort(l[:len(l)//2]),sort(l[len(l)//2:]))

_=list(range(1,1111))
r(_)
print(_)
print(sort(_))

Every time the recursion starts we add the recursion limit.

However

If you didn’t see any warning, it means that the recursion takes too long.

Which leads to...