Drop Python 3.5

notebook/_version.py

@@ -9,5 +9,5 @@ store the current version info of the notebook.
 
 # Next beta/alpha/rc release: The version number for beta is X.Y.ZbN **without dots**.
 
-version_info = (7, 0, 0, '.dev0')
+version_info = (6, 3, 0, '.dev0')
 __version__ = '.'.join(map(str, version_info[:3])) + ''.join(version_info[3:])

notebook/notebookapp.py

@@ -1611,9 +1611,6 @@ class NotebookApp(JupyterApp):
         )
         #  Ensure the appropriate version of Python and jupyter_client is available.
         if isinstance(self.kernel_manager, AsyncMappingKernelManager):
-            if sys.version_info < (3, 6):  # Can be removed once 3.5 is dropped.
-                raise ValueError("You are using `AsyncMappingKernelManager` in Python 3.5 (or lower) "
-                                 "which is not supported. Please upgrade Python to 3.6+ or change kernel managers.")
             if not async_kernel_mgmt_available:  # Can be removed once jupyter_client >= 6.1 is required.
                 raise ValueError("You are using `AsyncMappingKernelManager` without an appropriate "
                                  "jupyter_client installed!  Please upgrade jupyter_client or change kernel managers.")

notebook/services/kernels/tests/test_kernels_api.py

@@ -204,8 +204,6 @@ class AsyncKernelAPITest(KernelAPITest):
     def setup_class(cls):
         if not async_testing_enabled:  # Can be removed once jupyter_client >= 6.1 is required.
             raise SkipTest("AsyncKernelAPITest tests skipped due to down-level jupyter_client!")
-        if sys.version_info < (3, 6):  # Can be removed once 3.5 is dropped.
-            raise SkipTest("AsyncKernelAPITest tests skipped due to Python < 3.6!")
         super(AsyncKernelAPITest, cls).setup_class()
 
     @classmethod

notebook/services/sessions/tests/test_sessions_api.py

@@ -273,8 +273,6 @@ class AsyncSessionAPITest(SessionAPITest):
     def setup_class(cls):
         if not async_testing_enabled:  # Can be removed once jupyter_client >= 6.1 is required.
             raise SkipTest("AsyncSessionAPITest tests skipped due to down-level jupyter_client!")
-        if sys.version_info < (3, 6):  # Can be removed once 3.5 is dropped.
-            raise SkipTest("AsyncSessionAPITest tests skipped due to Python < 3.6!")
         super(AsyncSessionAPITest, cls).setup_class()
 
     @classmethod

notebook/static/base/js/namespace.js

@@ -73,7 +73,7 @@ define(function(){
     // tree
     jglobal('SessionList','tree/js/sessionlist');
 
-    Jupyter.version = "7.0.0.dev0";
+    Jupyter.version = "6.3.0.dev0";
     Jupyter._target = '_blank';
 
     return Jupyter;

setup.py

@@ -15,7 +15,7 @@ import sys
 
 name = "notebook"
 
-if sys.version_info < (3, 5):
+if sys.version_info < (3, 6):
     pip_message = 'This may be due to an out of date pip. Make sure you have pip >= 9.0.1.'
     try:
         import pip
@@ -31,7 +31,8 @@ if sys.version_info < (3, 5):
 
 
     error = """
-Notebook 6.0+ supports Python 3.5 and above.
+Notebook 6.3+ supports Python 3.6 and above.
+When using Python 3.5, please install Notebook <= 6.2.
 When using Python 3.4 or earlier (including 2.7), please install Notebook 5.x.
 
 Python {py} detected.
@@ -90,10 +91,10 @@ for more information.
         '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 :: 3.8',
+        'Programming Language :: Python :: 3.9'
     ],
     zip_safe = False,
     install_requires = [
@@ -121,7 +122,7 @@ for more information.
         'test:sys_platform != "win32"': ['requests-unixsocket'],
         'json-logging': ['json-logging']
     },
-    python_requires = '>=3.5',
+    python_requires = '>=3.6',
     entry_points = {
         'console_scripts': [
             'jupyter-notebook = notebook.notebookapp:main',