Merge pull request #1489 from satra/fix/ipyparallel_warning

fix: clarify ipython plugin usage - fixes #1451

Author: satra

doc/users/plugins.rst

@@ -92,7 +92,8 @@ machinery.
 .. note::
 
   We provide backward compatibility with IPython_ versions earlier than
-  0.10.1 using the IPythonX plugin.
+  0.10.1 using the IPythonX plugin. This plugin will be deprecated as of
+  version 0.13 of Nipype.
 
   Please read the IPython_ documentation to determine how to setup your cluster
   for distributed processing. This typically involves calling ipcluster.

nipype/pipeline/plugins/ipython.py

@@ -5,7 +5,6 @@
 
 from future import standard_library
 standard_library.install_aliases()
-
 from pickle import dumps
 
 import sys
@@ -47,7 +46,7 @@ class IPythonPlugin(DistributedPluginBase):
 
     def __init__(self, plugin_args=None):
         if IPython_not_loaded:
-            raise ImportError('ipyparallel could not be imported')
+            raise ImportError('Please install ipyparallel to use this plugin.')
         super(IPythonPlugin, self).__init__(plugin_args=plugin_args)
         self.iparallel = None
         self.taskclient = None
@@ -64,7 +63,7 @@ def run(self, graph, config, updatehash=False):
             __import__(name)
             self.iparallel = sys.modules[name]
         except ImportError:
-            raise ImportError("Ipython kernel not found. Parallel execution "
+            raise ImportError("ipyparallel not found. Parallel execution "
                               "will be unavailable")
         try:
             self.taskclient = self.iparallel.Client()

nipype/pipeline/plugins/ipythonx.py

@@ -5,11 +5,13 @@
 
 import sys
 
+from ...interfaces.base import LooseVersion
 IPython_not_loaded = False
 try:
     from IPython import __version__ as IPyversion
-    from IPython.kernel.contexts import ConnectionRefusedError
-except:
+    if LooseVersion(IPyversion) < LooseVersion('0.11'):
+        from IPython.kernel.contexts import ConnectionRefusedError
+except ImportError:
     IPython_not_loaded = True
 
 
@@ -21,6 +23,12 @@ class IPythonXPlugin(DistributedPluginBase):
     """
 
     def __init__(self, plugin_args=None):
+        if LooseVersion(IPyversion) > LooseVersion('0.10.1'):
+            raise EnvironmentError(('The IPythonX plugin can only be used with'
+                                    ' older IPython versions. Please use the '
+                                    'IPython plugin instead.'
+                                    ))
+        DeprecationWarning('This plugin will be deprecated as of version 0.13')
         if IPython_not_loaded:
             raise ImportError('ipyparallel could not be imported')
         super(IPythonXPlugin, self).__init__(plugin_args=plugin_args)