From 05bfcf38788982320d54550b3aeb0f5853aedb7f 2018-12-12 03:13:39
From: Jesse Widner <jwidner@mit.edu>
Date: 2018-12-12 03:13:39
Subject: [PATCH] Adds posix aliases after a %reset.

For example, running %reset in IPython, and then trying to run
%clear raises a UsageError.

---

diff --git a/IPython/core/interactiveshell.py b/IPython/core/interactiveshell.py
index f98e49c..a6c0ebb 100644
--- a/IPython/core/interactiveshell.py
+++ b/IPython/core/interactiveshell.py
@@ -1433,6 +1433,13 @@ class InteractiveShell(SingletonConfigurable):
         self.alias_manager.clear_aliases()
         self.alias_manager.init_aliases()
 
+        # Now define aliases that only make sense on the terminal, because they
+        # need direct access to the console in a way that we can't emulate in
+        # GUI or web frontend
+        if os.name == 'posix':
+            for cmd in ('clear', 'more', 'less', 'man'):
+                self.alias_manager.soft_define_alias(cmd, cmd)
+
         # Flush the private list of module references kept for script
         # execution protection
         self.clear_main_mod_cache()
diff --git a/IPython/core/tests/test_interactiveshell.py b/IPython/core/tests/test_interactiveshell.py
index 39fa41b..26dbd0d 100644
--- a/IPython/core/tests/test_interactiveshell.py
+++ b/IPython/core/tests/test_interactiveshell.py
@@ -495,6 +495,16 @@ class InteractiveShellTestCase(unittest.TestCase):
         self.assertFalse(ip.last_execution_result.success)
         self.assertIsInstance(ip.last_execution_result.error_in_exec, NameError)
 
+    def test_reset_aliasing(self):
+        """ Check that standard posix aliases work after %reset. """
+        if os.name != 'posix':
+            return
+
+        ip.reset()
+        for cmd in ('clear', 'more', 'less', 'man'):
+            res = ip.run_cell('%' + cmd)
+            self.assertEqual(res.success, True)
+
 
 class TestSafeExecfileNonAsciiPath(unittest.TestCase):
 
diff --git a/IPython/terminal/interactiveshell.py b/IPython/terminal/interactiveshell.py
index 6fc8980..d31cc6a 100644
--- a/IPython/terminal/interactiveshell.py
+++ b/IPython/terminal/interactiveshell.py
@@ -447,7 +447,7 @@ class TerminalInteractiveShell(InteractiveShell):
         # need direct access to the console in a way that we can't emulate in
         # GUI or web frontend
         if os.name == 'posix':
-            for cmd in ['clear', 'more', 'less', 'man']:
+            for cmd in ('clear', 'more', 'less', 'man'):
                 self.alias_manager.soft_define_alias(cmd, cmd)