skip find_cmd when setting up script magics

find_cmd was slow, and probably unnecessary anyway.

IPython/core/magics/script.py

@@ -30,7 +30,7 b' from IPython.core.magic import ('
 from IPython.lib.backgroundjobs import BackgroundJobManager
 from IPython.testing.skipdoctest import skip_doctest
 from IPython.utils import py3compat
-from IPython.utils.process import find_cmd, FindCmdError, arg_split
+from IPython.utils.process import arg_split
 from IPython.utils.traitlets import List, Dict
 
 #-----------------------------------------------------------------------------
@@ -90,36 +90,23 b' class ScriptMagics(Magics, Configurable):'
         """,
     )
     def _script_magics_default(self):
-        """default to a common list of programs if we find them"""
+        """default to a common list of programs"""
         
-        defaults = []
-        to_try = []
-        if os.name == 'nt':
-            defaults.append('cmd')
-            to_try.append('powershell')
-        to_try.extend([
+        defaults = [
             'sh',
             'bash',
             'perl',
             'ruby',
+            'python',
             'python3',
             'pypy',
-        ])
+        ]
+        if os.name == 'nt':
+            defaults.extend([
+                'cmd',
+                'powershell',
+            ])
         
-        for cmd in to_try:
-            if cmd in self.script_paths:
-                defaults.append(cmd)
-            else:
-                try:
-                    find_cmd(cmd)
-                except FindCmdError:
-                    # command not found, ignore it
-                    pass
-                except ImportError:
-                    # Windows without pywin32, find_cmd doesn't work
-                    pass
-                else:
-                    defaults.append(cmd)
         return defaults
     
     script_paths = Dict(config=True,