Return command to the next prompt if help was called halfway through a command. Also, ? at the end of a comment should not trigger help.

IPython/core/inputsplitter.py

@@ -70,6 +70,8 b' import ast'
 import codeop
 import re
 import sys
+import tokenize
+from StringIO import StringIO
 
 # IPython modules
 from IPython.utils.text import make_quoted_expr
@@ -155,6 +157,24 b' def remove_comments(src):'
     """
 
     return re.sub('#.*', '', src)
+    
+def has_comment(src):
+    """Indicate whether an input line has (i.e. ends in, or is) a comment.
+    
+    This uses tokenize, so it can distinguish comments from # inside strings.
+    
+    Parameters
+    ----------
+    src : string
+      A single line input string.
+    
+    Returns
+    -------
+    Boolean: True if source has a comment.
+    """
+    readline = StringIO(src).readline
+    toktypes = set(t[0] for t in tokenize.generate_tokens(readline))
+    return(tokenize.COMMENT in toktypes)
 
 
 def get_input_encoding():
@@ -672,12 +692,19 b' _help_end_re = re.compile(r"""(%?'
 def transform_help_end(line):
     """Translate lines with ?/?? at the end"""
     m = _help_end_re.search(line)
-    if m is None:
+    if m is None or has_comment(line):
         return line
     target = m.group(1)
     esc = m.group(3)
     lspace = _initial_space_re.match(line).group(0)
-    return _make_help_call(target, esc, lspace)
+    newline = _make_help_call(target, esc, lspace)
+    
+    # If we're mid-command, put it back on the next prompt for the user.
+    if line.strip() != m.group(0):
+        newline += "; get_ipython().set_next_input(%s)" % \
+                                        make_quoted_expr(line.rstrip('?'))
+        
+    return newline
 
 
 class EscapedTransformer(object):

IPython/core/tests/test_inputsplitter.py

@@ -25,6 +25,7 b' import nose.tools as nt'
 
 # Our own
 from IPython.core import inputsplitter as isp
+from IPython.testing import tools as tt
 
 #-----------------------------------------------------------------------------
 # Semi-complete examples (also used as tests)
@@ -92,9 +93,7 b' def test_spaces():'
              ('\tx', 1),
              ('\t x', 2),
              ]
-    
-    for s, nsp in tests:
-        nt.assert_equal(isp.num_ini_spaces(s), nsp)
+    tt.check_pairs(isp.num_ini_spaces, tests)
 
 
 def test_remove_comments():
@@ -106,9 +105,19 b' def test_remove_comments():'
              ('line # c \nline#c2  \nline\nline #c\n\n',
               'line \nline\nline\nline \n\n'),
              ]
-
-    for inp, out in tests:
-        nt.assert_equal(isp.remove_comments(inp), out)
+    tt.check_pairs(isp.remove_comments, tests)
+        
+def test_has_comment():
+    tests = [('text', False),
+             ('text #comment', True),
+             ('text #comment\n', True),
+             ('#comment', True),
+             ('#comment\n', True),
+             ('a = "#string"', False),
+             ('a = "#string" # comment', True),
+             ('a #comment not "string"', True),
+             ]
+    tt.check_pairs(isp.has_comment, tests)
 
 
 def test_get_input_encoding():
@@ -445,9 +454,10 b' syntax = \\'
         ('%hist?', 'get_ipython().magic(u"pinfo %hist")'),
         ('f*?', 'get_ipython().magic(u"psearch f*")'),
         ('ax.*aspe*?', 'get_ipython().magic(u"psearch ax.*aspe*")'),
-        ('a = abc?', 'get_ipython().magic(u"pinfo abc")'),
-        ('a = abc.qe??', 'get_ipython().magic(u"pinfo2 abc.qe")'),
-        ('a = *.items?', 'get_ipython().magic(u"psearch *.items")'),
+        ('a = abc?', 'get_ipython().magic(u"pinfo abc"); get_ipython().set_next_input(u"a = abc")'),
+        ('a = abc.qe??', 'get_ipython().magic(u"pinfo2 abc.qe"); get_ipython().set_next_input(u"a = abc.qe")'),
+        ('a = *.items?', 'get_ipython().magic(u"psearch *.items"); get_ipython().set_next_input(u"a = *.items")'),
+        ('a*2 #comment?', 'a*2 #comment?'),
         ],
 
        # Explicit magic calls
@@ -513,11 +523,11 b' syntax_ml = \\'
 
 
 def test_assign_system():
-    transform_checker(syntax['assign_system'], isp.transform_assign_system)
+    tt.check_pairs(isp.transform_assign_system, syntax['assign_system'])
 
     
 def test_assign_magic():
-    transform_checker(syntax['assign_magic'], isp.transform_assign_magic)
+    tt.check_pairs(isp.transform_assign_magic, syntax['assign_magic'])
 
 
 def test_classic_prompt():
@@ -532,34 +542,34 b' def test_ipy_prompt():'
         transform_checker(example, isp.transform_ipy_prompt)
 
 def test_end_help():
-    transform_checker(syntax['end_help'], isp.transform_help_end)
+    tt.check_pairs(isp.transform_help_end, syntax['end_help'])
 
 def test_escaped_noesc():
-    transform_checker(syntax['escaped_noesc'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_noesc'])
 
 
 def test_escaped_shell():
-    transform_checker(syntax['escaped_shell'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_shell'])
 
 
 def test_escaped_help():
-    transform_checker(syntax['escaped_help'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_help'])
 
 
 def test_escaped_magic():
-    transform_checker(syntax['escaped_magic'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_magic'])
 
 
 def test_escaped_quote():
-    transform_checker(syntax['escaped_quote'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_quote'])
 
 
 def test_escaped_quote2():
-    transform_checker(syntax['escaped_quote2'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_quote2'])
 
 
 def test_escaped_paren():
-    transform_checker(syntax['escaped_paren'], isp.transform_escaped)
+    tt.check_pairs(isp.transform_escaped, syntax['escaped_paren'])
 
 
 class IPythonInputTestCase(InputSplitterTestCase):