def _validate_mime_type(mime_type):
if utils.is_string(mime_type):
return mime_type.lower().strip()
# if not a string, mime_type has to be an enum
elif isinstance(mime_type, MIME_TYPE):
return mime_type.value
raise ValueError("Invalid MIME type: %s" % mime_type)
def do_execute (self, code, silent,
store_history, user_expressions, allow_stdin):
try:
# extract pre/post flight commands, if any
pre_flight_commands, post_flight_commands, user_code = \
self.magic_commands._parse_code(code)
# if there is no user code nor pre/post flight commands, do nothing
if (user_code.strip() == '') and \
(len(pre_flight_commands) == 0) and \
(len(post_flight_commands) == 0):
return
# (1/4) execute pre-flight magic commands, if any
for (mc_name, mc_function) in pre_flight_commands:
try:
# input: string; output: string (or None)
mc_output = mc_function(user_code)
except Exception as exception:
future.utils.raise_with_traceback(Exception(
"Error while running pre-flight command '%s': "
"%s" % (mc_name, exception)))
# output, if any, becomes the new user code
if (mc_output is not None):
assert utils.is_string(mc_output), (
"Invalid return value for pre-flight "
"magic command '%s': Must be a string" % mc_name)
user_code = mc_output
# (2/4) pass the user code to the kernel and retrieve frames
if (user_code.strip() == ''):
result_frames = []
else:
try:
_logger.debug("executing:\n%s" % user_code)
# input: string; output: generator
result_frames = self.do_execute_(user_code)
result_frames = renderers.core._check_frames(result_frames)
_logger.debug("executing: done")
except Exception as exception:
future.utils.raise_with_traceback(Exception(
"Error while evaluating user code: %s" % exception))
# (3/4) execute post-flight magic commands, if any
for (mc_name, mc_function) in post_flight_commands:
try:
# input: generator; output: generator
mc_output = mc_function(user_code, result_frames)
mc_output = renderers.core._check_frames(mc_output)
except Exception as exception:
future.utils.raise_with_traceback(Exception(
"Error while running post-flight command '%s': "
"%s" % (mc_name, exception)))
# output becomes the new result frame(s)
result_frames = mc_output
# (4/4) render the kernel results and send them to the notebook
if (silent):
_logger.debug("emitting nothing (silent notebook)")
else:
n_frames, n_subframes = 0, 0
for (mime_type, content, metadata) in result_frames:
# feed the content to any compatible renderer and
# send the resulting sub-frame(s) to the notebook
try:
subframes = renderers.core._render_content(
mime_type, content, metadata)
except Exception as exception:
future.utils.raise_with_traceback(Exception(exception))
for (mime_type_, content_, metadata_) in subframes:
length_ = len(content_)
metadata_ = {} if (metadata_ is None) else metadata_
if (mime_type_ == "text/plain"):
_logger.debug("emitting text"
" (%d %s)" % (
len(content_),
utils.plural("character", length_)))
response = ("stream", {
"name": "stdout",
"text": unicode(content_)})
else:
_logger.debug("emitting data"
" (%s, %d %s, metadata = %s)" % (
mime_type_,
len(content_),
utils.plural("byte", length_),
metadata_))
response = ("display_data", {
"metadata": metadata_,
"data": {mime_type_: content_}})
self.send_response(self.iopub_socket, *response)
n_subframes += 1
n_frames += 1
_logger.debug("emitted %d %s from %d %s" % (
n_subframes, utils.plural("subframe", n_subframes),
n_frames, utils.plural("frame", n_frames)))
except KeyboardInterrupt:
msg = "Execution aborted by user"
_logger.error(msg)
self.send_response(self.iopub_socket, "stream",
{"name": "stderr", "text": msg})
return {
"status": "abort",
"execution_count": self.execution_count}
except Exception as exception:
# retrieve the exception message (last line of traceback)
exc_type, exc_value, exc_traceback = sys.exc_info()
msg = traceback.format_exception_only(
exc_type, exc_value)[0].strip()
# if the exception is of type Exception, we strip the type
if (msg.startswith("Exception: ")):
msg = msg[11:]
# if the exception has no message attached, says so explicitly
if (str(exc_value).strip() == ''):
msg += "(no message)"
self.send_response(self.iopub_socket, "stream",
{"name": "stderr", "text": msg})
# create a more detailed error message for the
# logger, including the whole stack trace
stack, msg_ = traceback.extract_tb(exc_traceback), msg
for (file_name, line, func_name, text) in stack:
msg_ += "\n%s:%d in %s: %s" % (
file_name, line, func_name, text)
_logger.error(msg_)
return {
"status": "error",
"execution_count": self.execution_count,
"ename": exc_type.__name__,
"evalue": msg,
"traceback": stack}
# the execution happened without error
return {
"status": "ok",
"execution_count": self.execution_count,
"payload": [], # deprecated
"user_expressions": {}}