Fixed bugs with raw_input and finished and implementing InStream.

IPython/frontend/qt/console/console_widget.py

@@ -715,7 +715,7 b' class ConsoleWidget(QtGui.QPlainTextEdit):'
                                'is not visible!')
 
         self._reading = True
-        self._show_prompt(prompt)
+        self._show_prompt(prompt, newline=False)
 
         if callback is None:
             self._reading_callback = None
@@ -739,18 +739,25 b' class ConsoleWidget(QtGui.QPlainTextEdit):'
         """
         self.setTextCursor(self._get_selection_cursor(start, end))
 
-    def _show_prompt(self, prompt=None):
-        """ Writes a new prompt at the end of the buffer. If 'prompt' is not
-            specified, the previous prompt is used.
-        """
-        # Use QTextDocumentFragment intermediate object because it strips
-        # out the Unicode line break characters that Qt insists on inserting.
-        cursor = self._get_end_cursor()
-        if cursor.position() > 0:
-            cursor.movePosition(QtGui.QTextCursor.Left, 
-                                QtGui.QTextCursor.KeepAnchor)
-            if str(cursor.selection().toPlainText()) != '\n':
-                self.appendPlainText('\n')
+    def _show_prompt(self, prompt=None, newline=True):
+        """ Writes a new prompt at the end of the buffer.
+
+        Parameters
+        ----------
+        prompt : str, optional
+            The prompt to show. If not specified, the previous prompt is used.
+
+        newline : bool, optional (default True)
+            If set, a new line will be written before showing the prompt if 
+            there is not already a newline at the end of the buffer.
+        """
+        if newline:
+            cursor = self._get_end_cursor()
+            if cursor.position() > 0:
+                cursor.movePosition(QtGui.QTextCursor.Left, 
+                                    QtGui.QTextCursor.KeepAnchor)
+                if str(cursor.selection().toPlainText()) != '\n':
+                    self.appendPlainText('\n')
 
         if prompt is not None:
             self._prompt = prompt

IPython/frontend/qt/console/frontend_widget.py

@@ -143,12 +143,12 b' class FrontendWidget(HistoryConsoleWidget):'
     # 'ConsoleWidget' protected interface
     #---------------------------------------------------------------------------
 
-    def _show_prompt(self, prompt=None):
+    def _show_prompt(self, prompt=None, newline=True):
         """ Reimplemented to set a default prompt.
         """
         if prompt is None:
             prompt = '>>> '
-        super(FrontendWidget, self)._show_prompt(prompt)
+        super(FrontendWidget, self)._show_prompt(prompt, newline)
 
     #---------------------------------------------------------------------------
     # 'FrontendWidget' interface
@@ -297,6 +297,10 b' class FrontendWidget(HistoryConsoleWidget):'
             self._call_tip()
 
     def _handle_req(self, req):
+        # Make sure that all output from the SUB channel has been processed
+        # before entering readline mode.
+        self.kernel_manager.sub_channel.flush()
+
         def callback(line):
             self.kernel_manager.rep_channel.readline(line)
         self._readline(callback=callback)

IPython/zmq/kernel.py

@@ -13,11 +13,11 b' Things to do:'
 
 # Standard library imports.
 import __builtin__
+from code import CommandCompiler
 import os
 import sys
 import time
 import traceback
-from code import CommandCompiler
 
 # System library imports.
 import zmq
@@ -40,7 +40,7 b' class InStream(object):'
 
     def flush(self):
         if self.socket is None:
-            raise ValueError(u'I/O operation on closed file')
+            raise ValueError('I/O operation on closed file')
         
     def isatty(self):
         return False
@@ -49,19 +49,33 b' class InStream(object):'
         raise IOError('Seek not supported.')
 
     def read(self, size=-1):
-        raise NotImplementedError
+        # FIXME: Do we want another request for this?
+        string = '\n'.join(self.readlines())
+        return self._truncate(string, size)
 
     def readline(self, size=-1):
         if self.socket is None:
-            raise ValueError(u'I/O operation on closed file')
+            raise ValueError('I/O operation on closed file')
         else:
             content = dict(size=size)
             msg = self.session.msg('readline_request', content=content) 
             reply = self._request(msg)
-            return reply['content']['line']
+            line = reply['content']['line']
+            return self._truncate(line, size)
 
-    def readlines(self, size=-1):
-        raise NotImplementedError
+    def readlines(self, sizehint=-1):
+        # Sizehint is ignored, as is permitted.
+        if self.socket is None:
+            raise ValueError('I/O operation on closed file')
+        else:
+            lines = []
+            while True:
+                line = self.readline()
+                if line:
+                    lines.append(line)
+                else:
+                    break
+            return lines
 
     def seek(self, offset, whence=None):
         raise IOError('Seek not supported.')
@@ -73,6 +87,11 b' class InStream(object):'
         raise IOError('Write not supported on a read only stream.')
     
     def _request(self, msg):
+        # Flush output before making the request. This ensures, for example,
+        # that raw_input(prompt) actually gets a prompt written.
+        sys.stderr.flush()
+        sys.stdout.flush()
+
         self.socket.send_json(msg)
         while True:
             try:
@@ -86,6 +105,15 b' class InStream(object):'
                 break
         return reply
 
+    def _truncate(self, string, size):
+        if size >= 0:
+            if isinstance(string, str):
+                return string[:size]
+            elif isinstance(string, unicode):
+                encoded = string.encode('utf-8')[:size]
+                return encoded.decode('utf-8', 'ignore')
+        return string
+
 
 class OutStream(object):
     """A file like object that publishes the stream to a 0MQ PUB socket."""