help() now works just the same as vanilla help()

CHANGELOG

@@ -1,3 +1,12 @@
+v0.6.2
+======
+The help() now works (as far as I can see) exactly the same
+as the vanilla help() in the regular interpreter. I copied some
+code from pydoc.py to make it handle the special cases, e.g.
+help('keywords')
+help('modules')
+etc.
+
 v0.6.1
 ======
 Somehow it escaped my attention that the list window was never

bpython/_internal.py

@@ -1,23 +1,57 @@
 import pydoc
 import textwrap
 import sys
+import cStringIO
 
 # window has to be a global so that the main bpython.py can load it and
 # alter its state and share it with the interpreter being used for the
 # actual user input, I couldn't think of another way of doing this.
 window = None
 
-def _help( query ):
+def _help( obj ):
     """Wrapper for the regular help() function but with a ghetto
     PAGER since curses + less = :(
+    As per the vanilla help(), this function special-cases for str,
+    so you can do help('isinstance') or help(isinstance) and get the
+    same result.
     """
+    io = cStringIO.StringIO()
     doc = pydoc.TextDoc()
+    helper = pydoc.Helper( None, io )
+
     rows, columns = window.getmaxyx()
     rows -= 3
     columns -= 1
-    output = doc.document( query )
+    output = None
+
+#   Copied and pasted from Lib/pydoc.py and fiddled with
+#   so it works fine with bpython. As far as I can tell
+#   the bpython help is no compliant with the vanilla help.
+#   Please let me know if you find this to be untrue.
+    if type(obj) is type(''):
+        if obj == 'help': helper.intro()
+        elif obj == 'keywords': helper.listkeywords()
+        elif obj == 'topics': helper.listtopics()
+        elif obj == 'modules': helper.listmodules()
+        elif obj[:8] == 'modules ':
+            helper.listmodules(split(obj)[1])
+        elif obj in helper.keywords: helper.showtopic(obj)
+        elif obj in helper.topics: helper.showtopic(obj)
+        elif obj: output = doc.document( eval(obj) ) 
+#######################
+
+    else:
+        output = doc.document( obj )
+        if not output:
+            output = "No help found for %s" % obj
+            return
+
+    if output is None:
+        output = io.getvalue()
+        io.close()
+
     if not output:
-        output = "No help found for %s" % query
+        return
 
     output = output.replace('\t', '    ')