Add pathlib support for TEDLIUM (#1045)

test/torchaudio_unittest/datasets/tedlium_test.py

 import os
 import platform
 import unittest
+from pathlib import Path
 
 from torchaudio.datasets import tedlium
 
@@ -93,9 +94,7 @@ class Tedlium(TempDirMixin):
                 cls.samples[release].append(sample)
             seed += 1
 
-    def test_tedlium_release1(self):
-        release = "release1"
-        dataset = tedlium.TEDLIUM(self.root_dir, release=release)
+    def _test_tedlium(self, dataset, release):
         num_samples = 0
         for i, (data, sample_rate, transcript, talk_id, speaker_id, identifier) in enumerate(dataset):
             self.assertEqual(data, self.samples[release][i][0], atol=5e-5, rtol=1e-8)
@@ -113,45 +112,25 @@ class Tedlium(TempDirMixin):
         phoenemes = [f"{key} {' '.join(value)}" for key, value in phoneme_dict.items()]
         assert phoenemes == PHONEME
 
-    def test_tedlium_release2(self):
-        release = "release2"
+    def test_tedlium_release1_str(self):
+        release = "release1"
         dataset = tedlium.TEDLIUM(self.root_dir, release=release)
-        num_samples = 0
-        for i, (data, sample_rate, transcript, talk_id, speaker_id, identifier) in enumerate(dataset):
-            self.assertEqual(data, self.samples[release][i][0], atol=5e-5, rtol=1e-8)
-            assert sample_rate == self.samples[release][i][1]
-            assert transcript == self.samples[release][i][2]
-            assert talk_id == self.samples[release][i][3]
-            assert speaker_id == self.samples[release][i][4]
-            assert identifier == self.samples[release][i][5]
-            num_samples += 1
+        self._test_tedlium(dataset, release)
 
-        assert num_samples == len(self.samples[release])
+    def test_tedlium_release1_path(self):
+        release = "release1"
+        dataset = tedlium.TEDLIUM(Path(self.root_dir), release=release)
+        self._test_tedlium(dataset, release)
 
-        dataset._dict_path = os.path.join(dataset._path, f"{release}.dic")
-        phoneme_dict = dataset.phoneme_dict
-        phoenemes = [f"{key} {' '.join(value)}" for key, value in phoneme_dict.items()]
-        assert phoenemes == PHONEME
+    def test_tedlium_release2(self):
+        release = "release2"
+        dataset = tedlium.TEDLIUM(self.root_dir, release=release)
+        self._test_tedlium(dataset, release)
 
     def test_tedlium_release3(self):
         release = "release3"
         dataset = tedlium.TEDLIUM(self.root_dir, release=release)
-        num_samples = 0
-        for i, (data, sample_rate, transcript, talk_id, speaker_id, identifier) in enumerate(dataset):
-            self.assertEqual(data, self.samples[release][i][0], atol=5e-5, rtol=1e-8)
-            assert sample_rate == self.samples[release][i][1]
-            assert transcript == self.samples[release][i][2]
-            assert talk_id == self.samples[release][i][3]
-            assert speaker_id == self.samples[release][i][4]
-            assert identifier == self.samples[release][i][5]
-            num_samples += 1
-
-        assert num_samples == len(self.samples[release])
-
-        dataset._dict_path = os.path.join(dataset._path, f"{release}.dic")
-        phoneme_dict = dataset.phoneme_dict
-        phoenemes = [f"{key} {' '.join(value)}" for key, value in phoneme_dict.items()]
-        assert phoenemes == PHONEME
+        self._test_tedlium(dataset, release)
 
 
 class TestTedliumSoundfile(Tedlium, TorchaudioTestCase):

torchaudio/datasets/tedlium.py

 import os
-from typing import Tuple
+from typing import Tuple, Union
+from pathlib import Path
 
 import torchaudio
 from torch import Tensor
@@ -46,7 +47,7 @@ class TEDLIUM(Dataset):
     Create a Dataset for Tedlium. It supports releases 1,2 and 3.
 
     Args:
-        root (str): Path to the directory where the dataset is found or downloaded.
+        root (str or Path): Path to the directory where the dataset is found or downloaded.
         release (str, optional): Release version.
             Allowed values are ``"release1"``, ``"release2"`` or ``"release3"``.
             (default: ``"release1"``).
@@ -56,7 +57,12 @@ class TEDLIUM(Dataset):
             Whether to download the dataset if it is not found at root path. (default: ``False``).
     """
     def __init__(
-        self, root: str, release: str = "release1", subset: str = None, download: bool = False, audio_ext=".sph"
+        self,
+        root: Union[str, Path],
+        release: str = "release1",
+        subset: str = None,
+        download: bool = False,
+        audio_ext=".sph"
     ) -> None:
         self._ext_audio = audio_ext
         if release in _RELEASE_CONFIGS.keys():
@@ -78,6 +84,9 @@ class TEDLIUM(Dataset):
                 )
             )
 
+        # Get string representation of 'root' in case Path object is passed
+        root = os.fspath(root)
+
         basename = os.path.basename(url)
         archive = os.path.join(root, basename)