Merge pull request #6042 from minrk/import-less-than-everything

reduce a few implicit imports

IPython/html/services/clusters/clustermanager.py

@@ -21,7 +21,6 b' from zmq.eventloop import ioloop'
 
 from IPython.config.configurable import LoggingConfigurable
 from IPython.utils.traitlets import Dict, Instance, CFloat
-from IPython.parallel.apps.ipclusterapp import IPClusterStart
 from IPython.core.profileapp import list_profiles_in
 from IPython.core.profiledir import ProfileDir
 from IPython.utils import py3compat
@@ -33,17 +32,6 b' from IPython.utils.path import get_ipython_dir'
 #-----------------------------------------------------------------------------
 
 
-class DummyIPClusterStart(IPClusterStart):
-    """Dummy subclass to skip init steps that conflict with global app.
-    
-    Instantiating and initializing this class should result in fully configured
-    launchers, but no other side effects or state.
-    """
-
-    def init_signal(self):
-        pass
-    def reinit_logging(self):
-        pass
 
 
 class ClusterManager(LoggingConfigurable):
@@ -59,6 +47,20 b' class ClusterManager(LoggingConfigurable):'
         return IOLoop.instance()
 
     def build_launchers(self, profile_dir):
+        from IPython.parallel.apps.ipclusterapp import IPClusterStart
+        
+        class DummyIPClusterStart(IPClusterStart):
+            """Dummy subclass to skip init steps that conflict with global app.
+    
+            Instantiating and initializing this class should result in fully configured
+            launchers, but no other side effects or state.
+            """
+
+            def init_signal(self):
+                pass
+            def reinit_logging(self):
+                pass
+        
         starter = DummyIPClusterStart(log=self.log)
         starter.initialize(['--profile-dir', profile_dir])
         cl = starter.controller_launcher

IPython/kernel/connect.py

@@ -22,7 +22,6 b' from subprocess import Popen, PIPE'
 import tempfile
 
 import zmq
-from zmq.ssh import tunnel
 
 # IPython imports
 from IPython.config import LoggingConfigurable
@@ -342,6 +341,7 b' def tunnel_to_kernel(connection_info, sshserver, sshkey=None):'
     (shell, iopub, stdin, hb) : ints
         The four ports on localhost that have been forwarded to the kernel.
     """
+    from zmq.ssh import tunnel
     if isinstance(connection_info, string_types):
         # it's a path, unpack it
         with open(connection_info) as f:

IPython/parallel/client/client.py

@@ -18,7 +18,6 b' from pprint import pprint'
 pjoin = os.path.join
 
 import zmq
-from zmq.ssh import tunnel
 
 from IPython.config.configurable import MultipleInstanceError
 from IPython.core.application import BaseIPythonApplication
@@ -443,6 +442,7 b' class Client(HasTraits):'
             # default to ssh via localhost
             sshserver = addr
         if self._ssh and password is None:
+            from zmq.ssh import tunnel
             if tunnel.try_passwordless_ssh(sshserver, sshkey, paramiko):
                 password=False
             else:
@@ -467,6 +467,7 b' class Client(HasTraits):'
         self._query_socket = self._context.socket(zmq.DEALER)
 
         if self._ssh:
+            from zmq.ssh import tunnel
             tunnel.tunnel_connection(self._query_socket, cfg['registration'], sshserver, **ssh_kwargs)
         else:
             self._query_socket.connect(cfg['registration'])
@@ -589,6 +590,7 b' class Client(HasTraits):'
 
         def connect_socket(s, url):
             if self._ssh:
+                from zmq.ssh import tunnel
                 return tunnel.tunnel_connection(s, url, sshserver, **ssh_kwargs)
             else:
                 return s.connect(url)

IPython/parallel/client/map.py

@@ -4,56 +4,33 b''
 
 Scattering consists of partitioning a sequence and sending the various
 pieces to individual nodes in a cluster.
-
-
-Authors:
-
-* Brian Granger
-* MinRK
-
 """
 
-#-------------------------------------------------------------------------------
-#  Copyright (C) 2008-2011  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-------------------------------------------------------------------------------
-
-#-------------------------------------------------------------------------------
-# Imports
-#-------------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
 from __future__ import division
 
+import sys
 from itertools import islice
 
 from IPython.utils.data import flatten as utils_flatten
 
-#-------------------------------------------------------------------------------
-# Figure out which array packages are present and their array types
-#-------------------------------------------------------------------------------
-
-arrayModules = []
-try:
-    import Numeric
-except ImportError:
-    pass
-else:
-    arrayModules.append({'module':Numeric, 'type':Numeric.arraytype})
-try:
-    import numpy
-except ImportError:
-    pass
-else:
-    arrayModules.append({'module':numpy, 'type':numpy.ndarray})
-try:
-    import numarray
-except ImportError:
-    pass
-else:
-    arrayModules.append({'module':numarray,
-        'type':numarray.numarraycore.NumArray})
+
+numpy = None
+
+def is_array(obj):
+    """Is an object a numpy array?
+    
+    Avoids importing numpy until it is requested
+    """
+    global numpy
+    if 'numpy' not in sys.modules:
+        return False
+    
+    if numpy is None:
+        import numpy
+    return isinstance(obj, numpy.ndarray)
 
 class Map(object):
     """A class for partitioning a sequence using a map."""
@@ -90,14 +67,12 b' class Map(object):'
            
     def joinPartitions(self, listOfPartitions):
         return self.concatenate(listOfPartitions)
-                    
+    
     def concatenate(self, listOfPartitions):
         testObject = listOfPartitions[0]
         # First see if we have a known array type
-        for m in arrayModules:
-            #print m
-            if isinstance(testObject, m['type']):
-                return m['module'].concatenate(listOfPartitions)
+        if is_array(testObject):
+            return numpy.concatenate(listOfPartitions)
         # Next try for Python sequence types
         if isinstance(testObject, (list, tuple)):
             return utils_flatten(listOfPartitions)
@@ -117,19 +92,17 b' class RoundRobinMap(Map):'
     def joinPartitions(self, listOfPartitions):
         testObject = listOfPartitions[0]
         # First see if we have a known array type
-        for m in arrayModules:
-            #print m
-            if isinstance(testObject, m['type']):
-                return self.flatten_array(m['type'], listOfPartitions)
+        if is_array(testObject):
+            return self.flatten_array(listOfPartitions)
         if isinstance(testObject, (list, tuple)):
             return self.flatten_list(listOfPartitions)
         return listOfPartitions
     
-    def flatten_array(self, klass, listOfPartitions):
+    def flatten_array(self, listOfPartitions):
         test = listOfPartitions[0]
         shape = list(test.shape)
         shape[0] = sum([ p.shape[0] for p in listOfPartitions])
-        A = klass(shape)
+        A = numpy.ndarray(shape)
         N = shape[0]
         q = len(listOfPartitions)
         for p,part in enumerate(listOfPartitions):
@@ -141,23 +114,13 b' class RoundRobinMap(Map):'
         for i in range(len(listOfPartitions[0])):
             flat.extend([ part[i] for part in listOfPartitions if len(part) > i ])
         return flat
-        #lengths = [len(x) for x in listOfPartitions]
-        #maxPartitionLength = len(listOfPartitions[0])
-        #numberOfPartitions = len(listOfPartitions)
-        #concat = self.concatenate(listOfPartitions)
-        #totalLength = len(concat)
-        #result = []
-        #for i in range(maxPartitionLength):
-        #    result.append(concat[i:totalLength:maxPartitionLength])
-        # return self.concatenate(listOfPartitions)
 
 def mappable(obj):
     """return whether an object is mappable or not."""
     if isinstance(obj, (tuple,list)):
         return True
-    for m in arrayModules:
-        if isinstance(obj,m['type']):
-            return True
+    if is_array(obj):
+        return True
     return False
 
 dists = {'b':Map,'r':RoundRobinMap}

IPython/parallel/engine/engine.py

@@ -14,11 +14,10 b' from getpass import getpass'
 
 import zmq
 from zmq.eventloop import ioloop, zmqstream
-from zmq.ssh import tunnel
 
 from IPython.utils.localinterfaces import localhost
 from IPython.utils.traitlets import (
-    Instance, Dict, Integer, Type, Float, Integer, Unicode, CBytes, Bool
+    Instance, Dict, Integer, Type, Float, Unicode, CBytes, Bool
 )
 from IPython.utils.py3compat import cast_bytes
 
@@ -58,6 +57,11 b' class EngineFactory(RegistrationFactory):'
         help="""The SSH private key file to use when tunneling connections to the Controller.""")
     paramiko=Bool(sys.platform == 'win32', config=True,
         help="""Whether to use paramiko instead of openssh for tunnels.""")
+    
+    @property
+    def tunnel_mod(self):
+        from zmq.ssh import tunnel
+        return tunnel
 
 
     # not configurable:
@@ -97,7 +101,7 b' class EngineFactory(RegistrationFactory):'
             self.sshserver = self.url.split('://')[1].split(':')[0]
 
         if self.using_ssh:
-            if tunnel.try_passwordless_ssh(self.sshserver, self.sshkey, self.paramiko):
+            if self.tunnel_mod.try_passwordless_ssh(self.sshserver, self.sshkey, self.paramiko):
                 password=False
             else:
                 password = getpass("SSH Password for %s: "%self.sshserver)
@@ -108,7 +112,7 b' class EngineFactory(RegistrationFactory):'
             url = disambiguate_url(url, self.location)
             if self.using_ssh:
                 self.log.debug("Tunneling connection to %s via %s", url, self.sshserver)
-                return tunnel.tunnel_connection(s, url, self.sshserver,
+                return self.tunnel_mod.tunnel_connection(s, url, self.sshserver,
                             keyfile=self.sshkey, paramiko=self.paramiko,
                             password=password,
                 )
@@ -120,7 +124,7 b' class EngineFactory(RegistrationFactory):'
             url = disambiguate_url(url, self.location)
             if self.using_ssh:
                 self.log.debug("Tunneling connection to %s via %s", url, self.sshserver)
-                url,tunnelobj = tunnel.open_tunnel(url, self.sshserver,
+                url, tunnelobj = self.tunnel_mod.open_tunnel(url, self.sshserver,
                             keyfile=self.sshkey, paramiko=self.paramiko,
                             password=password,
                 )