Update conditional pyreadline3 dependency for Win

Author: KyleKing

Pipfile

@@ -22,7 +22,8 @@ ipython = "*"
 isort = "*"
 mock = {version = "*",markers = "python_version < '3.6'"}
 plumbum = "*"
-pyreadline = {version = "*",sys_platform = "== 'win32'"}
+pyreadline = {version = "*",sys_platform = "== 'win32'",markers = "python_version < '3.8'"}
+pyreadline3 = {version = "*",sys_platform = "== 'win32'",markers = "python_version >= '3.8'"}
 pytest = "*"
 pytest-cov = "*"
 pytest-mock = "*"

cmd2/rl_utils.py

@@ -37,8 +37,8 @@ class RlType(Enum):
 # Explanation for why readline wasn't loaded
 _rl_warn_reason = ''
 
-# The order of this check matters since importing pyreadline will also show readline in the modules list
-if 'pyreadline' in sys.modules:
+# The order of this check matters since importing pyreadline/pyreadline3 will also show readline in the modules list
+if 'pyreadline' in sys.modules or 'pyreadline3' in sys.modules:
     rl_type = RlType.PYREADLINE
 
     from ctypes import byref

docs/overview/integrating.rst

@@ -26,10 +26,13 @@ Windows Considerations
 
 If you would like to use :ref:`features/completion:Completion`, and you want
 your application to run on Windows, you will need to ensure you install the
-``pyreadline`` package. Make sure to include the following in your
-``setup.py``::
+``pyreadline3`` or ``pyreadline`` package. Make sure to include the following
+in your ``setup.py``::
 
   install_requires=[
     'cmd2>=1,<2',
-    ":sys_platform=='win32'": ['pyreadline'],
+    ":sys_platform=='win32'": [
+        "pyreadline ; python_version<'3.8'",
+        "pyreadline3 ; python_version>='3.8'",  # pyreadline3 is a drop-in replacement for Python 3.8 and above
+    ],
   ]

setup.py

@@ -44,8 +44,9 @@
 ]
 
 EXTRAS_REQUIRE = {
-    # Windows also requires pyreadline to ensure tab completion works
-    ":sys_platform=='win32'": ['pyreadline'],
+    # Windows also requires pyreadline or the replacement, pyreadline3, to ensure tab completion works
+    ":sys_platform=='win32' and python_version<'3.8'": ["pyreadline"],
+    ":sys_platform=='win32' and python_version>='3.8'": ["pyreadline3"],
     # Extra dependencies for running unit tests
     'test': [
         "gnureadline; sys_platform=='darwin'",  # include gnureadline on macOS to ensure it is available in nox env