Insert a fake pip magic warning users the should use the shell.

Ignore the pip by instance to let other magic overwrite it if necessary.

Thank Carol Willing and Thomas Kluyver for the phrasing

Bump  #9517 to 7.0

IPython/core/magics/basic.py

@@ -2,6 +2,7 b''
 
 
 import argparse
+import textwrap
 import io
 import sys
 from pprint import pformat
@@ -17,7 +18,8 b' from logging import error'
 
 
 class MagicsDisplay(object):
-    def __init__(self, magics_manager):
+    def __init__(self, magics_manager, ignore=None):
+        self.ignore = ignore if ignore else []
         self.magics_manager = magics_manager
     
     def _lsmagic(self):
@@ -27,10 +29,10 b' class MagicsDisplay(object):'
         mman = self.magics_manager
         magics = mman.lsmagic()
         out = ['Available line magics:',
-               mesc + ('  '+mesc).join(sorted(magics['line'])),
+               mesc + ('  '+mesc).join(sorted([m for m,v in magics['line'].items() if (v not in self.ignore)])),
                '',
                'Available cell magics:',
-               cesc + ('  '+cesc).join(sorted(magics['cell'])),
+               cesc + ('  '+cesc).join(sorted([m for m,v in magics['cell'].items() if (v not in self.ignore)])),
                '',
                mman.auto_status()]
         return '\n'.join(out)
@@ -160,7 +162,7 b' class BasicMagics(Magics):'
     @line_magic
     def lsmagic(self, parameter_s=''):
         """List currently available magic functions."""
-        return MagicsDisplay(self.shell.magics_manager)
+        return MagicsDisplay(self.shell.magics_manager, ignore=[self.pip])
 
     def _magic_docs(self, brief=False, rest=False):
         """Return docstrings from magic functions."""
@@ -377,7 +379,24 b' Currently the magic system has the following functions:""",'
             xmode_switch_err('user')
 
     @line_magic
-    def quickref(self,arg):
+    def pip(self, args=''):
+        """
+        Intercept usage of ``pip`` in IPython and direct user to run command outside of IPython.
+        """
+        print(textwrap.dedent('''
+        The following command must be run outside of the IPython shell:
+
+            $ pip {args}
+
+        The Python package manager (pip) can only be used from outside of IPython.
+        Please reissue the `pip` command in a separate terminal or command prompt.
+
+        See the Python documentation for more informations on how to install packages:
+
+            https://docs.python.org/3/installing/'''.format(args=args)))
+
+    @line_magic
+    def quickref(self, arg):
         """ Show a quick reference sheet """
         from IPython.core.usage import quick_reference
         qr = quick_reference + self._magic_docs(brief=True)