Backport PR #11076: Disable Jedi completions by default

IPython/core/completer.py

@@ -576,9 +576,9 b' class Completer(Configurable):'
         """
     ).tag(config=True)
 
-    use_jedi = Bool(default_value=JEDI_INSTALLED,
+    use_jedi = Bool(default_value=False,
                     help="Experimental: Use Jedi to generate autocompletions. "
-                    "Default to True if jedi is installed").tag(config=True)
+                    "Off by default.").tag(config=True)
 
     jedi_compute_type_timeout = Int(default_value=400,
         help="""Experimental: restrict time (in milliseconds) during which Jedi can compute types.

IPython/core/tests/test_completer.py

@@ -316,13 +316,17 b' def test_jedi():'
         start = start if start is not None else l
         end = end if end is not None else l
         with provisionalcompleter():
+            ip.Completer.use_jedi = True
             completions = set(ip.Completer.completions(s, l))
+            ip.Completer.use_jedi = False
             assert_in(Completion(start, end, comp), completions, reason)
 
     def _test_not_complete(reason, s, comp):
         l = len(s)
         with provisionalcompleter():
+            ip.Completer.use_jedi = True
             completions = set(ip.Completer.completions(s, l))
+            ip.Completer.use_jedi = False
             assert_not_in(Completion(l, l, comp), completions, reason)
 
     import jedi
@@ -341,8 +345,10 b' def test_completion_have_signature():'
     """
     ip = get_ipython()
     with provisionalcompleter():
+        ip.Completer.use_jedi = True
         completions = ip.Completer.completions('ope', 3)
         c = next(completions)  # should be `open`
+        ip.Completer.use_jedi = False
     assert 'file' in c.signature, "Signature of function was not found by completer"
     assert 'encoding' in c.signature, "Signature of function was not found by completer"
 
@@ -357,7 +363,9 b' def test_deduplicate_completions():'
         zoo = 1
     '''))
     with provisionalcompleter():
+        ip.Completer.use_jedi = True
         l = list(_deduplicate_completions('Z.z', ip.Completer.completions('Z.z', 3)))
+        ip.Completer.use_jedi = False
 
     assert len(l) == 1, 'Completions (Z.z<tab>) correctly deduplicate: %s ' % l
     assert l[0].text == 'zoo'  # and not `it.accumulate`

docs/source/whatsnew/version6.rst

@@ -3,6 +3,18 b''
 ============
 
 
+.. _whatsnew631:
+
+IPython 6.3.1
+=============
+
+This is a bugfix release to switch the default completions back to IPython's
+own completion machinery. We discovered some problems with the completions
+from Jedi, including completing column names on pandas data frames.
+
+You can switch the completions source with the config option
+:configtrait:`Completer.use_jedi`.
+
 .. _whatsnew630:
 
 IPython 6.3