Make torchaudio work on Python 2. (#209)

- Apply __future__ imports uniformly (future division is the biggy, but absolute
  imports mattered too)
- Hotfix use of tempfile.TemporaryDirectory using a BC library (DO NOT
  add this library as a dependency to torchaudio; it's only for testing)
- Replace math.gcd with fractions.gcd
- Fix a weird pytest collection bug involving parametrized tests
- Turn on Python 2 and Python 3.7 in Travis.

Signed-off-by: Edward Z. Yang <ezyang@fb.com>

Author: ezyang

.travis.yml

@@ -12,10 +12,11 @@ cache:
 matrix:
   fast_finish: true
   include:
-    # TODO add this back in when there is a pytorch 1.2 for python 3.5
-    # - env: PYTHON_VERSION="3.5"
+    - env: PYTHON_VERSION="3.7"
     - env: PYTHON_VERSION="3.6"
+    # TODO add this back in when there is a pytorch 1.2 for python 3.5
     - env: PYTHON_VERSION="3.5" RUN_FLAKE8="true" SKIP_TESTS="true"
+    - env: PYTHON_VERSION="2.7"
 
 addons:
   apt:

requirements.txt

@@ -14,4 +14,7 @@ librosa>=0.4.3
 scipy
 
 # Unit tests with pytest
-pytest
+pytest
+
+# Testing only Py3 compat
+backports.tempfile

test/common_utils.py

@@ -1,6 +1,7 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import os
 from shutil import copytree
-import tempfile
+import backports.tempfile as tempfile
 import torch
 
 TEST_DIR_PATH = os.path.dirname(os.path.realpath(__file__))

test/compliance/generate_fbank_data.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import argparse
 import logging
 import os

test/compliance/generate_test_stft_data.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import argparse
 import logging
 import os

test/compliance/utils.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import random
 import torchaudio
 

test/test.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import unittest
 import common_utils
 import torch

test/test_compliance_kaldi.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import math
 import os
 import common_utils

test/test_dataloader.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import unittest
 import common_utils
 import torch

test/test_datasets_vctk.py

@@ -1,3 +1,4 @@
+from __future__ import absolute_import, division, print_function, unicode_literals
 import os
 
 import torch