In [1]:

kernel = get_ipython().kernel

In [2]:

kernel._parent_header

Out[2]:

{'buffers': [],
 'content': {'allow_stdin': True,
  'code': 'kernel._parent_header',
  'silent': False,
  'stop_on_error': True,
  'store_history': True,
  'user_expressions': {}},
 'header': {'date': '2016-10-11T11:30:07.988220',
  'msg_id': '0DAA2B1585244A89979BFC7F296399D0',
  'msg_type': 'execute_request',
  'session': '249381749DEA42C89E8E4266F8D28FC5',
  'username': 'username',
  'version': '5.0'},
 'metadata': {},
 'msg_id': '0DAA2B1585244A89979BFC7F296399D0',
 'msg_type': 'execute_request',
 'parent_header': {}}

In [3]:

import sys
from contextlib import contextmanager

@contextmanager
def temp_parent(parent_ident, parent_header):
    """Context manager temporarily setting the parent header
    
    for routing output to a particular cell
    """
    save_parent = (kernel._parent_ident, kernel._parent_header)
    sys.stdout.flush()
    sys.stderr.flush()
    kernel.set_parent(parent_ident, parent_header)
    try:
        yield
    finally:
        sys.stdout.flush()
        sys.stderr.flush()
        kernel.set_parent(*save_parent)

In [4]:

def from_this_cell(arg, *, show=print):
    with temp_parent(*from_this_cell.target):
        show(arg)

from_this_cell.target = (kernel._parent_ident, kernel._parent_header)

# workaround frontend:
# prevent the status:idle message from firing for this cell,
# because the frontend will discard callbacks once
# idle indicates that output is complete.
_save_status = kernel._publish_status
def _disable_once(*args, **kw):
    kernel._publish_status = _save_status
kernel._publish_status = _disable_once

Up there!

In [5]:

print("I'm here")
from_this_cell("Up there!")
print("back")

I'm here
back