Time complexity of string slice

Question

What\'s the time complexity of slicing a Python string? Given that Python strings are immutable, I can imagine slicing them being either O(1) or O(n)

Answer 1

Passing around the indices is not so bad if you just pack them in together in an object

from dataclasses import dataclass

@dataclass
class StrSlice:
    str: str
    start: int
    end: int

def middle(slice):
    return slice.str[(slice.start + slice.end) // 2]

def reverse(slice):
    return slice.str[slice.start : slice.end][::-1]

def length(slice):
    return slice.end - slice.start

def chars(slice):
    yield from (slice.str[i] for i in range(slice.start, slice.end)

def equals(slice1, slice2):
    if length(slice1) != length(slice2):
        return False
    return all(c1 == c2 for c1, c2 in zip(chars(slice1), chars(slice2))