IPython refuses to update the namespace. fix scrapy#396

IPython embedding code borrowed from pallets/werkzeug#85

Author: dangra

scrapy/utils/console.py

@@ -1,21 +1,25 @@
 
-def start_python_console(namespace=None, noipython=False):
+def start_python_console(namespace=None, noipython=False, banner=''):
     """Start Python console binded to the given namespace. If IPython is
     available, an IPython console will be started instead, unless `noipython`
     is True. Also, tab completion will be used on Unix systems.
     """
     if namespace is None:
         namespace = {}
+
     try:
         try: # use IPython if available
             if noipython:
-                raise ImportError
-            import IPython
+                raise ImportError()
+
             try:
-                IPython.embed(user_ns=namespace)
-            except AttributeError:
-                shell = IPython.Shell.IPShellEmbed(argv=[], user_ns=namespace)
-                shell()
+                from IPython.frontend.terminal.embed import InteractiveShellEmbed
+                sh = InteractiveShellEmbed(banner1=banner)
+            except ImportError:
+                from IPython.Shell import IPShellEmbed
+                sh = IPShellEmbed(banner=banner)
+
+            sh(global_ns={}, local_ns=namespace)
         except ImportError:
             import code
             try: # readline module is only available on unix systems
@@ -25,6 +29,6 @@ def start_python_console(namespace=None, noipython=False):
             else:
                 import rlcompleter
                 readline.parse_and_bind("tab:complete")
-            code.interact(banner='', local=namespace)
+            code.interact(banner=banner, local=namespace)
     except SystemExit: # raised when using exit() in python code.interact
         pass