|
|
# -*- coding: utf-8 -*-
|
|
|
"""Displayhook for IPython.
|
|
|
|
|
|
This defines a callable class that IPython uses for `sys.displayhook`.
|
|
|
"""
|
|
|
|
|
|
# Copyright (c) IPython Development Team.
|
|
|
# Distributed under the terms of the Modified BSD License.
|
|
|
|
|
|
import builtins as builtin_mod
|
|
|
import sys
|
|
|
import io as _io
|
|
|
import tokenize
|
|
|
|
|
|
from traitlets.config.configurable import Configurable
|
|
|
from traitlets import Instance, Float
|
|
|
from warnings import warn
|
|
|
|
|
|
# TODO: Move the various attributes (cache_size, [others now moved]). Some
|
|
|
# of these are also attributes of InteractiveShell. They should be on ONE object
|
|
|
# only and the other objects should ask that one object for their values.
|
|
|
|
|
|
class DisplayHook(Configurable):
|
|
|
"""The custom IPython displayhook to replace sys.displayhook.
|
|
|
|
|
|
This class does many things, but the basic idea is that it is a callable
|
|
|
that gets called anytime user code returns a value.
|
|
|
"""
|
|
|
|
|
|
shell = Instance('IPython.core.interactiveshell.InteractiveShellABC',
|
|
|
allow_none=True)
|
|
|
exec_result = Instance('IPython.core.interactiveshell.ExecutionResult',
|
|
|
allow_none=True)
|
|
|
cull_fraction = Float(0.2)
|
|
|
|
|
|
def __init__(self, shell=None, cache_size=1000, **kwargs):
|
|
|
super(DisplayHook, self).__init__(shell=shell, **kwargs)
|
|
|
cache_size_min = 3
|
|
|
if cache_size <= 0:
|
|
|
self.do_full_cache = 0
|
|
|
cache_size = 0
|
|
|
elif cache_size < cache_size_min:
|
|
|
self.do_full_cache = 0
|
|
|
cache_size = 0
|
|
|
warn('caching was disabled (min value for cache size is %s).' %
|
|
|
cache_size_min,stacklevel=3)
|
|
|
else:
|
|
|
self.do_full_cache = 1
|
|
|
|
|
|
self.cache_size = cache_size
|
|
|
|
|
|
# we need a reference to the user-level namespace
|
|
|
self.shell = shell
|
|
|
|
|
|
self._,self.__,self.___ = '','',''
|
|
|
|
|
|
# these are deliberately global:
|
|
|
to_user_ns = {'_':self._,'__':self.__,'___':self.___}
|
|
|
self.shell.user_ns.update(to_user_ns)
|
|
|
|
|
|
@property
|
|
|
def prompt_count(self):
|
|
|
return self.shell.execution_count
|
|
|
|
|
|
#-------------------------------------------------------------------------
|
|
|
# Methods used in __call__. Override these methods to modify the behavior
|
|
|
# of the displayhook.
|
|
|
#-------------------------------------------------------------------------
|
|
|
|
|
|
def check_for_underscore(self):
|
|
|
"""Check if the user has set the '_' variable by hand."""
|
|
|
# If something injected a '_' variable in __builtin__, delete
|
|
|
# ipython's automatic one so we don't clobber that. gettext() in
|
|
|
# particular uses _, so we need to stay away from it.
|
|
|
if '_' in builtin_mod.__dict__:
|
|
|
try:
|
|
|
user_value = self.shell.user_ns['_']
|
|
|
if user_value is not self._:
|
|
|
return
|
|
|
del self.shell.user_ns['_']
|
|
|
except KeyError:
|
|
|
pass
|
|
|
|
|
|
def quiet(self):
|
|
|
"""Should we silence the display hook because of ';'?"""
|
|
|
# do not print output if input ends in ';'
|
|
|
|
|
|
try:
|
|
|
cell = self.shell.history_manager.input_hist_parsed[-1]
|
|
|
except IndexError:
|
|
|
# some uses of ipshellembed may fail here
|
|
|
return False
|
|
|
|
|
|
return self.semicolon_at_end_of_expression(cell)
|
|
|
|
|
|
@staticmethod
|
|
|
def semicolon_at_end_of_expression(expression):
|
|
|
"""Parse Python expression and detects whether last token is ';'"""
|
|
|
|
|
|
sio = _io.StringIO(expression)
|
|
|
tokens = list(tokenize.generate_tokens(sio.readline))
|
|
|
|
|
|
for token in reversed(tokens):
|
|
|
if token[0] in (tokenize.ENDMARKER, tokenize.NL, tokenize.NEWLINE, tokenize.COMMENT):
|
|
|
continue
|
|
|
if (token[0] == tokenize.OP) and (token[1] == ';'):
|
|
|
return True
|
|
|
else:
|
|
|
return False
|
|
|
|
|
|
def start_displayhook(self):
|
|
|
"""Start the displayhook, initializing resources."""
|
|
|
pass
|
|
|
|
|
|
def write_output_prompt(self):
|
|
|
"""Write the output prompt.
|
|
|
|
|
|
The default implementation simply writes the prompt to
|
|
|
``sys.stdout``.
|
|
|
"""
|
|
|
# Use write, not print which adds an extra space.
|
|
|
sys.stdout.write(self.shell.separate_out)
|
|
|
outprompt = 'Out[{}]: '.format(self.shell.execution_count)
|
|
|
if self.do_full_cache:
|
|
|
sys.stdout.write(outprompt)
|
|
|
|
|
|
def compute_format_data(self, result):
|
|
|
"""Compute format data of the object to be displayed.
|
|
|
|
|
|
The format data is a generalization of the :func:`repr` of an object.
|
|
|
In the default implementation the format data is a :class:`dict` of
|
|
|
key value pair where the keys are valid MIME types and the values
|
|
|
are JSON'able data structure containing the raw data for that MIME
|
|
|
type. It is up to frontends to determine pick a MIME to to use and
|
|
|
display that data in an appropriate manner.
|
|
|
|
|
|
This method only computes the format data for the object and should
|
|
|
NOT actually print or write that to a stream.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
result : object
|
|
|
The Python object passed to the display hook, whose format will be
|
|
|
computed.
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
(format_dict, md_dict) : dict
|
|
|
format_dict is a :class:`dict` whose keys are valid MIME types and values are
|
|
|
JSON'able raw data for that MIME type. It is recommended that
|
|
|
all return values of this should always include the "text/plain"
|
|
|
MIME type representation of the object.
|
|
|
md_dict is a :class:`dict` with the same MIME type keys
|
|
|
of metadata associated with each output.
|
|
|
|
|
|
"""
|
|
|
return self.shell.display_formatter.format(result)
|
|
|
|
|
|
# This can be set to True by the write_output_prompt method in a subclass
|
|
|
prompt_end_newline = False
|
|
|
|
|
|
def write_format_data(self, format_dict, md_dict=None) -> None:
|
|
|
"""Write the format data dict to the frontend.
|
|
|
|
|
|
This default version of this method simply writes the plain text
|
|
|
representation of the object to ``sys.stdout``. Subclasses should
|
|
|
override this method to send the entire `format_dict` to the
|
|
|
frontends.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
format_dict : dict
|
|
|
The format dict for the object passed to `sys.displayhook`.
|
|
|
md_dict : dict (optional)
|
|
|
The metadata dict to be associated with the display data.
|
|
|
"""
|
|
|
if 'text/plain' not in format_dict:
|
|
|
# nothing to do
|
|
|
return
|
|
|
# We want to print because we want to always make sure we have a
|
|
|
# newline, even if all the prompt separators are ''. This is the
|
|
|
# standard IPython behavior.
|
|
|
result_repr = format_dict['text/plain']
|
|
|
if '\n' in result_repr:
|
|
|
# So that multi-line strings line up with the left column of
|
|
|
# the screen, instead of having the output prompt mess up
|
|
|
# their first line.
|
|
|
# We use the prompt template instead of the expanded prompt
|
|
|
# because the expansion may add ANSI escapes that will interfere
|
|
|
# with our ability to determine whether or not we should add
|
|
|
# a newline.
|
|
|
if not self.prompt_end_newline:
|
|
|
# But avoid extraneous empty lines.
|
|
|
result_repr = '\n' + result_repr
|
|
|
|
|
|
try:
|
|
|
print(result_repr)
|
|
|
except UnicodeEncodeError:
|
|
|
# If a character is not supported by the terminal encoding replace
|
|
|
# it with its \u or \x representation
|
|
|
print(result_repr.encode(sys.stdout.encoding,'backslashreplace').decode(sys.stdout.encoding))
|
|
|
|
|
|
def update_user_ns(self, result):
|
|
|
"""Update user_ns with various things like _, __, _1, etc."""
|
|
|
|
|
|
# Avoid recursive reference when displaying _oh/Out
|
|
|
if self.cache_size and result is not self.shell.user_ns['_oh']:
|
|
|
if len(self.shell.user_ns['_oh']) >= self.cache_size and self.do_full_cache:
|
|
|
self.cull_cache()
|
|
|
|
|
|
# Don't overwrite '_' and friends if '_' is in __builtin__
|
|
|
# (otherwise we cause buggy behavior for things like gettext). and
|
|
|
# do not overwrite _, __ or ___ if one of these has been assigned
|
|
|
# by the user.
|
|
|
update_unders = True
|
|
|
for unders in ['_'*i for i in range(1,4)]:
|
|
|
if not unders in self.shell.user_ns:
|
|
|
continue
|
|
|
if getattr(self, unders) is not self.shell.user_ns.get(unders):
|
|
|
update_unders = False
|
|
|
|
|
|
self.___ = self.__
|
|
|
self.__ = self._
|
|
|
self._ = result
|
|
|
|
|
|
if ('_' not in builtin_mod.__dict__) and (update_unders):
|
|
|
self.shell.push({'_':self._,
|
|
|
'__':self.__,
|
|
|
'___':self.___}, interactive=False)
|
|
|
|
|
|
# hackish access to top-level namespace to create _1,_2... dynamically
|
|
|
to_main = {}
|
|
|
if self.do_full_cache:
|
|
|
new_result = '_%s' % self.prompt_count
|
|
|
to_main[new_result] = result
|
|
|
self.shell.push(to_main, interactive=False)
|
|
|
self.shell.user_ns['_oh'][self.prompt_count] = result
|
|
|
|
|
|
def fill_exec_result(self, result):
|
|
|
if self.exec_result is not None:
|
|
|
self.exec_result.result = result
|
|
|
|
|
|
def log_output(self, format_dict):
|
|
|
"""Log the output."""
|
|
|
if 'text/plain' not in format_dict:
|
|
|
# nothing to do
|
|
|
return
|
|
|
if self.shell.logger.log_output:
|
|
|
self.shell.logger.log_write(format_dict['text/plain'], 'output')
|
|
|
self.shell.history_manager.output_hist_reprs[self.prompt_count] = \
|
|
|
format_dict['text/plain']
|
|
|
|
|
|
def finish_displayhook(self):
|
|
|
"""Finish up all displayhook activities."""
|
|
|
sys.stdout.write(self.shell.separate_out2)
|
|
|
sys.stdout.flush()
|
|
|
|
|
|
def __call__(self, result=None):
|
|
|
"""Printing with history cache management.
|
|
|
|
|
|
This is invoked every time the interpreter needs to print, and is
|
|
|
activated by setting the variable sys.displayhook to it.
|
|
|
"""
|
|
|
self.check_for_underscore()
|
|
|
if result is not None and not self.quiet():
|
|
|
self.start_displayhook()
|
|
|
self.write_output_prompt()
|
|
|
format_dict, md_dict = self.compute_format_data(result)
|
|
|
self.update_user_ns(result)
|
|
|
self.fill_exec_result(result)
|
|
|
if format_dict:
|
|
|
self.write_format_data(format_dict, md_dict)
|
|
|
self.log_output(format_dict)
|
|
|
self.finish_displayhook()
|
|
|
|
|
|
def cull_cache(self):
|
|
|
"""Output cache is full, cull the oldest entries"""
|
|
|
oh = self.shell.user_ns.get('_oh', {})
|
|
|
sz = len(oh)
|
|
|
cull_count = max(int(sz * self.cull_fraction), 2)
|
|
|
warn('Output cache limit (currently {sz} entries) hit.\n'
|
|
|
'Flushing oldest {cull_count} entries.'.format(sz=sz, cull_count=cull_count))
|
|
|
|
|
|
for i, n in enumerate(sorted(oh)):
|
|
|
if i >= cull_count:
|
|
|
break
|
|
|
self.shell.user_ns.pop('_%i' % n, None)
|
|
|
oh.pop(n, None)
|
|
|
|
|
|
|
|
|
def flush(self):
|
|
|
if not self.do_full_cache:
|
|
|
raise ValueError("You shouldn't have reached the cache flush "
|
|
|
"if full caching is not enabled!")
|
|
|
# delete auto-generated vars from global namespace
|
|
|
|
|
|
for n in range(1,self.prompt_count + 1):
|
|
|
key = '_'+repr(n)
|
|
|
try:
|
|
|
del self.shell.user_ns[key]
|
|
|
except: pass
|
|
|
# In some embedded circumstances, the user_ns doesn't have the
|
|
|
# '_oh' key set up.
|
|
|
oh = self.shell.user_ns.get('_oh', None)
|
|
|
if oh is not None:
|
|
|
oh.clear()
|
|
|
|
|
|
# Release our own references to objects:
|
|
|
self._, self.__, self.___ = '', '', ''
|
|
|
|
|
|
if '_' not in builtin_mod.__dict__:
|
|
|
self.shell.user_ns.update({'_':self._,'__':self.__,'___':self.___})
|
|
|
import gc
|
|
|
# TODO: Is this really needed?
|
|
|
# IronPython blocks here forever
|
|
|
if sys.platform != "cli":
|
|
|
gc.collect()
|
|
|
|
|
|
|
|
|
class CapturingDisplayHook(object):
|
|
|
def __init__(self, shell, outputs=None):
|
|
|
self.shell = shell
|
|
|
if outputs is None:
|
|
|
outputs = []
|
|
|
self.outputs = outputs
|
|
|
|
|
|
def __call__(self, result=None):
|
|
|
if result is None:
|
|
|
return
|
|
|
format_dict, md_dict = self.shell.display_formatter.format(result)
|
|
|
self.outputs.append({ 'data': format_dict, 'metadata': md_dict })
|
|
|
|
