Drop python 3.5 support.

As @willingc said in jupyter-widgets#3120 (comment): “Version 8.0 of widgets should drop 3.5 as it has reached [End-of-Life](https://devguide.python.org/#status-of-python-branches) and lacks good support for async and does not have f-strings.”

.github/workflows/tests.yml

@@ -98,7 +98,7 @@ jobs:
  strategy:
  max-parallel: 4
  matrix:
- python-version: [3.5, 3.6, 3.7, 3.8]
+ python-version: [3.6, 3.7, 3.8, 3.9]
 
  steps:
  - uses: actions/checkout@v2
@@ -128,7 +128,7 @@ jobs:
  - name: Set up Python
  uses: actions/setup-python@v1
  with:
- python-version: 3.5
+ python-version: 3.6
  - uses: actions/cache@v1
  with:
  path: ~/.cache/pip

setup.py

@@ -78,17 +78,18 @@
  'License :: OSI Approved :: BSD License',
  'Programming Language :: Python',
  'Programming Language :: Python :: 3',
- 'Programming Language :: Python :: 3.5',
  'Programming Language :: Python :: 3.6',
  'Programming Language :: Python :: 3.7',
+ 'Programming Language :: Python :: 3.8',
+ 'Programming Language :: Python :: 3.9',
  'Programming Language :: Python :: 3 :: Only',
  'Framework :: Jupyter'
  ],
  cmdclass = {
  'build_py': build_py,
  'sdist': sdist,
  },
- python_requires = '>=3.5',
+ python_requires = '>=3.6',
 )
 
 if 'develop' in sys.argv or any(a.startswith('bdist') for a in sys.argv):
@@ -107,10 +108,10 @@
  # interpreter, to allow ipywidgets to be
  # installed on bare kernels.
  'widgetsnbextension~=4.0a0',
+ 'jupyterlab_widgets~=2.0a0'
 ]
 
 extras_require = setuptools_args['extras_require'] = {
- ':python_version>="3.6"': ['jupyterlab_widgets~=2.0a0'],
  'test': ['pytest>=3.6.0', 'pytest-cov'],
 }
 

widgetsnbextension/setup.py

@@ -34,12 +34,6 @@
 
 import sys
 
-v = sys.version_info
-if v[:2] < (3, 5):
- error = "ERROR: %s requires Python version 3.5 or above." % name
- print(error, file=sys.stderr)
- sys.exit(1)
-
 #-----------------------------------------------------------------------------
 # get on with it
 #-----------------------------------------------------------------------------
@@ -204,6 +198,7 @@ def run(self):
  ],
  zip_safe=False,
  include_package_data = True,
+ python_requires = '>=3.6'
 )
 
 if 'develop' in sys.argv or any(a.startswith('bdist') for a in sys.argv):