Add option for specifying Python executable to 'launch_kernel'.

IPython/zmq/entry_point.py

@@ -155,7 +155,7 b' def make_default_main(kernel_factory):'
 
 
 def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,
-                       independent=False, extra_arguments=[]):
+                       executable=None, independent=False, extra_arguments=[]):
     """ Launches a localhost kernel, binding to the specified ports.
 
     Parameters
@@ -175,6 +175,9 b' def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     hb_port : int, optional
         The port to use for the hearbeat REP channel.
 
+    executable : str, optional (default sys.executable)
+        The Python executable to use for the kernel process.
+
     independent : bool, optional (default False) 
         If set, the kernel process is guaranteed to survive if this process
         dies. If not set, an effort is made to ensure that the kernel is killed
@@ -212,7 +215,9 b' def base_launch_kernel(code, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
         hb_port = ports.pop(0)
 
     # Build the kernel launch command.
-    arguments = [ sys.executable, '-c', code, '--xrep', str(xrep_port), 
+    if executable is None:
+        executable = sys.executable
+    arguments = [ executable, '-c', code, '--xrep', str(xrep_port), 
                   '--pub', str(pub_port), '--req', str(req_port),
                   '--hb', str(hb_port) ]
     arguments.extend(extra_arguments)

IPython/zmq/ipkernel.py

@@ -551,7 +551,7 b' class GTKKernel(Kernel):'
 #-----------------------------------------------------------------------------
 
 def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,
-                  independent=False, pylab=False, colors=None):
+                  executable=None, independent=False, pylab=False, colors=None):
     """Launches a localhost kernel, binding to the specified ports.
 
     Parameters
@@ -571,6 +571,9 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     hb_port : int, optional
         The port to use for the hearbeat REP channel.
 
+    executable : str, optional (default sys.executable)
+        The Python executable to use for the kernel process.
+
     independent : bool, optional (default False) 
         If set, the kernel process is guaranteed to survive if this process
         dies. If not set, an effort is made to ensure that the kernel is killed
@@ -605,7 +608,7 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
         extra_arguments.append(colors)
     return base_launch_kernel('from IPython.zmq.ipkernel import main; main()',
                               xrep_port, pub_port, req_port, hb_port, 
-                              independent, extra_arguments)
+                              executable, independent, extra_arguments)
 
 
 def main():

IPython/zmq/pykernel.py

@@ -248,7 +248,7 b' class Kernel(HasTraits):'
 #-----------------------------------------------------------------------------
 
 def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,
-                  independent=False):
+                  executable=None, independent=False):
     """ Launches a localhost kernel, binding to the specified ports.
 
     Parameters
@@ -268,6 +268,9 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     hb_port : int, optional
         The port to use for the hearbeat REP channel.
 
+    executable : str, optional (default sys.executable)
+        The Python executable to use for the kernel process.
+
     independent : bool, optional (default False) 
         If set, the kernel process is guaranteed to survive if this process
         dies. If not set, an effort is made to ensure that the kernel is killed
@@ -288,7 +291,8 b' def launch_kernel(ip=None, xrep_port=0, pub_port=0, req_port=0, hb_port=0,'
     
     return base_launch_kernel('from IPython.zmq.pykernel import main; main()',
                               xrep_port, pub_port, req_port, hb_port,
-                              independent, extra_arguments=extra_arguments)
+                              executable, independent,
+                              extra_arguments=extra_arguments)
 
 main = make_default_main(Kernel)