From 65c80f94c11666e9a4e9140024af3e0be3150986 Mon Sep 17 00:00:00 2001
From: Anthony Scopatz <scopatz@gmail.com>
Date: Wed, 8 Nov 2017 21:42:58 -0500
Subject: [PATCH] updated python completer to allow for initial open paren

---
 news/openparen.rst         | 15 +++++++++++++++
 xonsh/completers/python.py |  2 +-
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 news/openparen.rst

diff --git a/news/openparen.rst b/news/openparen.rst
new file mode 100644
index 000000000..baa910853
--- /dev/null
+++ b/news/openparen.rst
@@ -0,0 +1,15 @@
+**Added:** None
+
+**Changed:** None
+
+**Deprecated:** None
+
+**Removed:** None
+
+**Fixed:**
+
+* Starting a new command with an open parentheses will no longer
+  throw a traceback when ``$UPDATE_COMPLETIONS_ON_KEYPRESS`` is
+  ``True``.
+
+**Security:** None
diff --git a/xonsh/completers/python.py b/xonsh/completers/python.py
index 059ec15d1..11ad1ab6c 100644
--- a/xonsh/completers/python.py
+++ b/xonsh/completers/python.py
@@ -169,7 +169,7 @@ def python_signature_complete(prefix, line, end, ctx, filter_func):
         return set()
     funcname = xt.subexpr_before_unbalanced(front, '(', ')')
     val, _ctx = _safe_eval(funcname, ctx)
-    if val is None and _ctx is None:
+    if val is None:
         return set()
     try:
         sig = inspect.signature(val)