Use setuptools_scm

Follows up ufoym#47

- on [pypi](https://pypi.org/project/torchsampler/0.1.1/) it's 0.1.1
- on github it's [0.1.0](https://github.com/ufoym/imbalanced-dataset-sampler/releases/tag/v0.1.0)
    - but the attached [wheel](https://github.com/ufoym/imbalanced-dataset-sampler/releases/download/v0.1.0/torchsampler-0.1.1-py3-none-any.whl)
      and [sdist](https://github.com/ufoym/imbalanced-dataset-sampler/releases/download/v0.1.0/torchsampler-0.1.1.tar.gz) are 0.1.1

[`setuptools-scm`](https://pypi.org/project/setuptools-scm/) makes git the single-source of truth
for the version of the package, and works well with the build script in ufoym#47 (which is triggered
by tagging a new version in git).

`setuptools-scm` also replaces most of MANIFEST.in, so this removes the
redundant lines from that too.

.github/workflows/ci_install-pkg.yml

@@ -19,8 +19,6 @@ jobs:
 
       - name: Check package
         run: |
-          pip install check-manifest
-          check-manifest
           python setup.py check --metadata --strict
 
       - name: Create package

MANIFEST.in

@@ -1,24 +1,11 @@
-# Manifest syntax https://docs.python.org/2/distutils/sourcedist.html
-graft wheelhouse
+# Manifest syntax https://setuptools.pypa.io/en/latest/deprecated/distutils/commandref.html#sdist-cmd
 
-recursive-exclude __pycache__  *.py[cod] *.orig
-
-# Include the README
-include *.md
-
-# Include the license file
-include LICENSE
-
-recursive-include torchsampler *.py
-
-# Include the Requirements
-include requirements.txt
+# FIXME: switching to a src/ layout would obviate the need for this file entirely.
+#        see https://setuptools.pypa.io/en/latest/userguide/package_discovery.html#src-layout
 
 # Exclude build configs
 exclude *.yml
 exclude *.yaml
 
 prune .github
 prune example*
-prune temp*
-prune test*

requirements.txt

@@ -1,3 +1,4 @@
 torch>=1.3
 torchvision>=0.5
 pandas
+importlib_metadata; python_version<'3.8'

setup.py

@@ -20,7 +20,7 @@
 
 setup(
     name='torchsampler',
-    version=about.__version__,
+    use_scm_version=True,
     url=about.__homepage__,
     author=about.__author__,
     author_email=about.__author_email__,
@@ -30,6 +30,7 @@
     long_description_content_type='text/markdown',
     packages=['torchsampler'],
     keywords='sampler,pytorch,dataloader',
+    setup_requires=['setuptools_scm'],
     install_requires=requirements,
     python_requires='>=3.6',
     include_package_data=True,

torchsampler/__about__.py

@@ -1,3 +1,15 @@
+import sys
+
+if sys.version_info < (3, 8):
+    from importlib_metadata import PackageNotFoundError, version
+else:
+    from importlib.metadata import PackageNotFoundError, version
+
+try:
+    __version__ = version("torchsampler")
+except PackageNotFoundError:
+    # package is not installed (i.e. we're probably in the build process itself)
+    pass
 __version__ = "0.1.1"
 __author__ = "Ming, et al."
 __author_email__ = "a@ufoym.com"