From 73441e41c14d8bc086ad5db7c5ba5b83cbd08991 2013-11-15 00:40:54
From: Paul Ivanov <pi@berkeley.edu>
Date: 2013-11-15 00:40:54
Subject: [PATCH] custom keyboard interrupt handling in  ask_yes_no

Sometimes, Ctrl-C just makes sense as an answer, and re-asking the
question is just frustrating. This changes makes it possible to break
out of the asking loop via Ctrl-C. This is particularly handy for asking
questions from the command line, where one expects Ctrl-c to be a sort
of "Cancel" operation, and is often functionally equivalent to "no"

---

diff --git a/IPython/utils/io.py b/IPython/utils/io.py
index 46296be..088c5be 100644
--- a/IPython/utils/io.py
+++ b/IPython/utils/io.py
@@ -155,11 +155,13 @@ class Tee(object):
             self.close()
 
 
-def ask_yes_no(prompt,default=None):
+def ask_yes_no(prompt, default=None, interrupt=None):
     """Asks a question and returns a boolean (y/n) answer.
 
     If default is given (one of 'y','n'), it is used if the user input is
-    empty. Otherwise the question is repeated until an answer is given.
+    empty. If interrupt is given (one of 'y','n'), it is used if the user
+    presses Ctrl-C. Otherwise the question is repeated until an answer is
+    given.
 
     An EOF is treated as the default answer.  If there is no default, an
     exception is raised to prevent infinite loops.
@@ -174,7 +176,8 @@ def ask_yes_no(prompt,default=None):
             if not ans:  # response was an empty string
                 ans = default
         except KeyboardInterrupt:
-            pass
+            if interrupt:
+                ans = interrupt
         except EOFError:
             if default in answers.keys():
                 ans = default