Add publish workflow and version

Author: chuanchenlv

.github/workflows/publish-to-pypi.yml

@@ -0,0 +1,26 @@
+name: "Publish to PyPI"
+on:
+  release:
+    types:
+      - published
+jobs:
+  build-n-publish:
+    name: Build and publish
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: '3.7'
+          architecture: 'x64'
+      - name: Run build script
+        run: |
+          echo "VERSION = \"${GITHUB_REF##refs/tags/v}\"" > OpenHowNet/version.py
+          pip install twine --user
+          pip install wheel
+          python setup.py sdist bdist_wheel
+      - name: Publish a Python distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+            user: __token__
+            password: ${{ secrets.PYPI_API_TOKEN }}

OpenHowNet/version.py

@@ -0,0 +1 @@
+VERSION = "test"

setup.py

@@ -1,6 +1,8 @@
 import setuptools
 
 VERSION = "test"
+with open("OpenHowNet/version.py", "r") as fver:
+    VERSION = fver.read().replace("VERSION", "").replace("=", "").replace("\"", "").strip()
 
 with open("README.md", "r", encoding="utf-8") as fh:
     long_description = '<h1 align="center">OpenHowNet</h1>\n'+fh.read().split('### [中文版本](README_ZH.md)\n\n')[1]