bpo-39314: Closes parenthesis when autocompleting for functions that take no arguments (GH-20562)

1 files changed, 8 insertions, 1 deletions

diff --git a/Lib/rlcompleter.py b/Lib/rlcompleter.py
index bca4a7b..c06388e 100644
--- a/Lib/rlcompleter.py
+++ b/Lib/rlcompleter.py
@@ -31,6 +31,7 @@ Notes:
 
 import atexit
 import builtins
+import inspect
 import __main__
 
 __all__ = ["Completer"]
@@ -96,7 +97,13 @@ class Completer:
 
     def _callable_postfix(self, val, word):
         if callable(val):
-            word = word + "("
+            word += "("
+            try:
+                if not inspect.signature(val).parameters:
+                    word += ")"
+            except ValueError:
+                pass
+
         return word
 
     def global_matches(self, text):