Add pathlib.Path support for download utils (#8196)

Co-authored-by: Ahmad Sharif <ahmads@fb.com>
Co-authored-by: Brizar <1500595+bmmtstb@users.noreply.github.com>
Co-authored-by: Nicolas Hug <contact@nicolas-hug.com>

test/test_internet.py

@@ -6,6 +6,7 @@ cleanly ignored in FB internal test infra.
 """
 
 import os
+import pathlib
 from urllib.error import URLError
 
 import pytest
@@ -13,7 +14,10 @@ import torchvision.datasets.utils as utils
 
 
 class TestDatasetUtils:
-    def test_download_url(self, tmpdir):
+    @pytest.mark.parametrize("use_pathlib", (True, False))
+    def test_download_url(self, tmpdir, use_pathlib):
+        if use_pathlib:
+            tmpdir = pathlib.Path(tmpdir)
         url = "http://github.com/pytorch/vision/archive/master.zip"
         try:
             utils.download_url(url, tmpdir)
@@ -21,7 +25,10 @@ class TestDatasetUtils:
         except URLError:
             pytest.skip(f"could not download test file '{url}'")
 
-    def test_download_url_retry_http(self, tmpdir):
+    @pytest.mark.parametrize("use_pathlib", (True, False))
+    def test_download_url_retry_http(self, tmpdir, use_pathlib):
+        if use_pathlib:
+            tmpdir = pathlib.Path(tmpdir)
         url = "https://github.com/pytorch/vision/archive/master.zip"
         try:
             utils.download_url(url, tmpdir)
@@ -29,12 +36,18 @@ class TestDatasetUtils:
         except URLError:
             pytest.skip(f"could not download test file '{url}'")
 
-    def test_download_url_dont_exist(self, tmpdir):
+    @pytest.mark.parametrize("use_pathlib", (True, False))
+    def test_download_url_dont_exist(self, tmpdir, use_pathlib):
+        if use_pathlib:
+            tmpdir = pathlib.Path(tmpdir)
         url = "http://github.com/pytorch/vision/archive/this_doesnt_exist.zip"
         with pytest.raises(URLError):
             utils.download_url(url, tmpdir)
 
-    def test_download_url_dispatch_download_from_google_drive(self, mocker, tmpdir):
+    @pytest.mark.parametrize("use_pathlib", (True, False))
+    def test_download_url_dispatch_download_from_google_drive(self, mocker, tmpdir, use_pathlib):
+        if use_pathlib:
+            tmpdir = pathlib.Path(tmpdir)
         url = "https://drive.google.com/file/d/1GO-BHUYRuvzr1Gtp2_fqXRsr9TIeYbhV/view"
 
         id = "1GO-BHUYRuvzr1Gtp2_fqXRsr9TIeYbhV"
@@ -44,7 +57,7 @@ class TestDatasetUtils:
         mocked = mocker.patch("torchvision.datasets.utils.download_file_from_google_drive")
         utils.download_url(url, tmpdir, filename, md5)
 
-        mocked.assert_called_once_with(id, tmpdir, filename, md5)
+        mocked.assert_called_once_with(id, os.path.expanduser(tmpdir), filename, md5)
 
 
 if __name__ == "__main__":

torchvision/datasets/utils.py

@@ -15,7 +15,7 @@ import urllib.error
 import urllib.request
 import warnings
 import zipfile
-from typing import Any, Callable, Dict, IO, Iterable, Iterator, List, Optional, Tuple, TypeVar
+from typing import Any, Callable, Dict, IO, Iterable, Iterator, List, Optional, Tuple, TypeVar, Union
 from urllib.parse import urlparse
 
 import numpy as np
@@ -104,7 +104,11 @@ def _get_google_drive_file_id(url: str) -> Optional[str]:
 
 
 def download_url(
-    url: str, root: str, filename: Optional[str] = None, md5: Optional[str] = None, max_redirect_hops: int = 3
+    url: str,
+    root: Union[str, pathlib.Path],
+    filename: Optional[str] = None,
+    md5: Optional[str] = None,
+    max_redirect_hops: int = 3,
 ) -> None:
     """Download a file from a url and place it in root.
 
@@ -118,7 +122,7 @@ def download_url(
     root = os.path.expanduser(root)
     if not filename:
         filename = os.path.basename(url)
-    fpath = os.path.join(root, filename)
+    fpath = os.fspath(os.path.join(root, filename))
 
     os.makedirs(root, exist_ok=True)
 
@@ -203,7 +207,9 @@ def _extract_gdrive_api_response(response, chunk_size: int = 32 * 1024) -> Tuple
     return api_response, content
 
 
-def download_file_from_google_drive(file_id: str, root: str, filename: Optional[str] = None, md5: Optional[str] = None):
+def download_file_from_google_drive(
+    file_id: str, root: Union[str, pathlib.Path], filename: Optional[str] = None, md5: Optional[str] = None
+):
     """Download a Google Drive file from  and place it in root.
 
     Args:
@@ -217,7 +223,7 @@ def download_file_from_google_drive(file_id: str, root: str, filename: Optional[
     root = os.path.expanduser(root)
     if not filename:
         filename = file_id
-    fpath = os.path.join(root, filename)
+    fpath = os.fspath(os.path.join(root, filename))
 
     os.makedirs(root, exist_ok=True)