Fix DTD partition validation using and instead of or

[Osamaali313]

Problem

DTD.__init__ (torchvision/datasets/dtd.py) validates the partition argument with and:

if not isinstance(partition, int) and not (1 <= partition <= 10):
    raise ValueError(
        f"Parameter 'partition' should be an integer with `1 <= partition <= 10`, "
        f"but got {partition} instead"
    )

The intent is to reject any value that isn't an int in [1, 10]. The correct predicate is not (isinstance(partition, int) and 1 <= partition <= 10), which by De Morgan is not isinstance(...) or not (1 <= ... <= 10). With and, the error fires only when the value is both a non-int and out of range — so a normal out-of-range int like 11 (not isinstance(11, int) → False) short-circuits the and to False and passes validation.

Impact

DTD(root, partition=11) (or 0, -3) slips past the check and then dies later at:

open(self._meta_folder / f"{self._split}{self._partition}.txt")

with an opaque FileNotFoundError: ...train11.txt instead of the documented ValueError. A str partition like "1" raises TypeError from 1 <= "1" for the same reason (the or fix short-circuits before the comparison and handles that too). torchvision.datasets.DTD is public and partition is a documented constructor arg; the error message in this very statement documents the contract the guard fails to enforce.

Reproduction

partition	before (and)	after (or)
1, 10	accepted	accepted
11, 0, -3	accepted ❌ (later FileNotFoundError)	ValueError ✅
"1"	TypeError	ValueError ✅

Fix

if not isinstance(partition, int) or not (1 <= partition <= 10):

[pytorch-bot]

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