Allow getting help mid-way through a command (e.g. a = abc.def?).

IPython/core/inputsplitter.py

@@ -658,6 +658,34 b' def transform_ipy_prompt(line):'
         return line
 
 
+def _make_help_call(target, esc, lspace):
+    """Prepares a pinfo(2)/psearch call from a target name and the escape
+    (i.e. ? or ??)"""
+    method  = 'pinfo2' if esc == '??' \
+                else 'psearch' if '*' in target \
+                else 'pinfo'
+        
+    tpl = '%sget_ipython().magic(u"%s %s")'
+    return tpl % (lspace, method, target)
+
+_initial_space_re = re.compile(r'\s*')
+_help_end_re = re.compile(r"""(%?
+                              [a-zA-Z_*][a-zA-Z0-9_*]*       # Variable name
+                              (.[a-zA-Z_*][a-zA-Z0-9_*]*)*   # .etc.etc
+                              )
+                              (\?\??)$                       # ? or ??""",
+                              re.VERBOSE)
+def transform_help_end(line):
+    """Translate lines with ?/?? at the end"""
+    m = _help_end_re.search(line)
+    if m is None:
+        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)
+
+
 class EscapedTransformer(object):
     """Class to transform lines that are explicitly escaped out."""
 
@@ -694,28 +722,8 b' class EscapedTransformer(object):'
         # A naked help line should just fire the intro help screen
         if not line_info.line[1:]:
             return 'get_ipython().show_usage()'
-
-        # There may be one or two '?' at the end, move them to the front so that
-        # the rest of the logic can assume escapes are at the start
-        l_ori = line_info
-        line = line_info.line
-        if line.endswith('?'):
-            line = line[-1] + line[:-1]
-        if line.endswith('?'):
-            line = line[-1] + line[:-1]
-        line_info = LineInfo(line)
-
-        # From here on, simply choose which level of detail to get, and
-        # special-case the psearch syntax
-        pinfo = 'pinfo' # default
-        if '*' in line_info.line:
-            pinfo = 'psearch'
-        elif line_info.esc == '??':
-            pinfo = 'pinfo2'
-
-        tpl = '%sget_ipython().magic(u"%s %s")'
-        return tpl % (line_info.lspace, pinfo,
-                      ' '.join([line_info.fpart, line_info.rest]).strip())
+        
+        return _make_help_call(line_info.fpart, line_info.esc, line_info.lspace)
 
     @staticmethod
     def _tr_magic(line_info):
@@ -756,14 +764,9 b' class EscapedTransformer(object):'
         # Get line endpoints, where the escapes can be
         line_info = LineInfo(line)
 
-        # If the escape is not at the start, only '?' needs to be special-cased.
-        # All other escapes are only valid at the start
         if not line_info.esc in self.tr:
-            if line.endswith(ESC_HELP):
-                return self._tr_help(line_info)
-            else:
-                # If we don't recognize the escape, don't modify the line
-                return line
+            # If we don't recognize the escape, don't modify the line
+            return line
 
         return self.tr[line_info.esc](line_info)
 
@@ -815,9 +818,9 b' class IPythonInputSplitter(InputSplitter):'
 
         lines_list = lines.splitlines()
 
-        transforms = [transform_escaped, transform_assign_system,
-                      transform_assign_magic, transform_ipy_prompt,
-                      transform_classic_prompt]
+        transforms = [transform_escaped, transform_help_end,
+                      transform_assign_system, transform_assign_magic,
+                      transform_ipy_prompt, transform_classic_prompt]
 
         # Transform logic
         #

IPython/core/tests/test_inputsplitter.py

@@ -434,12 +434,21 b' syntax = \\'
        [ ('?', 'get_ipython().show_usage()'),
          ('?x1', 'get_ipython().magic(u"pinfo x1")'),
          ('??x2', 'get_ipython().magic(u"pinfo2 x2")'),
-         ('x3?', 'get_ipython().magic(u"pinfo x3")'),
-         ('x4??', 'get_ipython().magic(u"pinfo2 x4")'),
-         ('%hist?', 'get_ipython().magic(u"pinfo %hist")'),
-         ('f*?', 'get_ipython().magic(u"psearch f*")'),
-         ('ax.*aspe*?', 'get_ipython().magic(u"psearch ax.*aspe*")'),
+         ('?a.*s', 'get_ipython().magic(u"psearch a.*s")'),
+         ('?%hist', 'get_ipython().magic(u"pinfo %hist")'),
+         ('?abc = qwe', 'get_ipython().magic(u"pinfo abc")'),
          ],
+         
+      end_help =
+      [ ('x3?', 'get_ipython().magic(u"pinfo x3")'),
+        ('x4??', 'get_ipython().magic(u"pinfo2 x4")'),
+        ('%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")'),
+        ],
 
        # Explicit magic calls
        escaped_magic =
@@ -513,7 +522,9 b' def test_ipy_prompt():'
     transform_checker(syntax['ipy_prompt'], isp.transform_ipy_prompt)
     for example in syntax_ml['ipy_prompt']:
         transform_checker(example, isp.transform_ipy_prompt)
-    
+
+def test_end_help():
+    transform_checker(syntax['end_help'], isp.transform_help_end)
 
 def test_escaped_noesc():
     transform_checker(syntax['escaped_noesc'], isp.transform_escaped)