##// END OF EJS Templates
Avoid loading readline in the kernel...
Avoid loading readline in the kernel This bit of code was loading readline even when there was no need for it. In a Qt console or notebook, try: 'readline' in sys.modules 'gnureadline' in sys.modules I plan to rework this code more extensively once we've switched to prompt_toolkit, but for now, this little fix should make the kernel start slightly faster.

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interactiveshell.py
807 lines | 30.4 KiB | text/x-python | PythonLexer
# -*- coding: utf-8 -*-
"""Subclass of InteractiveShell for terminal based frontends."""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
from __future__ import print_function
import bdb
import os
import sys
from IPython.core.error import TryNext, UsageError
from IPython.core.usage import interactive_usage
from IPython.core.inputsplitter import IPythonInputSplitter, ESC_MAGIC
from IPython.core.interactiveshell import InteractiveShell, InteractiveShellABC
from IPython.core.magic import Magics, magics_class, line_magic
from IPython.lib.clipboard import ClipboardEmpty
from IPython.utils.contexts import NoOpContext
from IPython.utils.decorators import undoc
from IPython.utils.encoding import get_stream_enc
from IPython.utils import py3compat
from IPython.utils.terminal import toggle_set_term_title, set_term_title
from IPython.utils.process import abbrev_cwd
from IPython.utils.warn import warn, error
from IPython.utils.text import num_ini_spaces, SList, strip_email_quotes
from traitlets import Integer, CBool, Unicode
def get_default_editor():
try:
ed = os.environ['EDITOR']
if not py3compat.PY3:
ed = ed.decode()
return ed
except KeyError:
pass
except UnicodeError:
warn("$EDITOR environment variable is not pure ASCII. Using platform "
"default editor.")
if os.name == 'posix':
return 'vi' # the only one guaranteed to be there!
else:
return 'notepad' # same in Windows!
def get_pasted_lines(sentinel, l_input=py3compat.input, quiet=False):
""" Yield pasted lines until the user enters the given sentinel value.
"""
if not quiet:
print("Pasting code; enter '%s' alone on the line to stop or use Ctrl-D." \
% sentinel)
prompt = ":"
else:
prompt = ""
while True:
try:
l = py3compat.str_to_unicode(l_input(prompt))
if l == sentinel:
return
else:
yield l
except EOFError:
print('<EOF>')
return
@undoc
def no_op(*a, **kw): pass
class ReadlineNoRecord(object):
"""Context manager to execute some code, then reload readline history
so that interactive input to the code doesn't appear when pressing up."""
def __init__(self, shell):
self.shell = shell
self._nested_level = 0
def __enter__(self):
if self._nested_level == 0:
try:
self.orig_length = self.current_length()
self.readline_tail = self.get_readline_tail()
except (AttributeError, IndexError): # Can fail with pyreadline
self.orig_length, self.readline_tail = 999999, []
self._nested_level += 1
def __exit__(self, type, value, traceback):
self._nested_level -= 1
if self._nested_level == 0:
# Try clipping the end if it's got longer
try:
e = self.current_length() - self.orig_length
if e > 0:
for _ in range(e):
self.shell.readline.remove_history_item(self.orig_length)
# If it still doesn't match, just reload readline history.
if self.current_length() != self.orig_length \
or self.get_readline_tail() != self.readline_tail:
self.shell.refill_readline_hist()
except (AttributeError, IndexError):
pass
# Returning False will cause exceptions to propagate
return False
def current_length(self):
return self.shell.readline.get_current_history_length()
def get_readline_tail(self, n=10):
"""Get the last n items in readline history."""
end = self.shell.readline.get_current_history_length() + 1
start = max(end-n, 1)
ghi = self.shell.readline.get_history_item
return [ghi(x) for x in range(start, end)]
@magics_class
class TerminalMagics(Magics):
def __init__(self, shell):
super(TerminalMagics, self).__init__(shell)
self.input_splitter = IPythonInputSplitter()
def store_or_execute(self, block, name):
""" Execute a block, or store it in a variable, per the user's request.
"""
if name:
# If storing it for further editing
self.shell.user_ns[name] = SList(block.splitlines())
print("Block assigned to '%s'" % name)
else:
b = self.preclean_input(block)
self.shell.user_ns['pasted_block'] = b
self.shell.using_paste_magics = True
try:
self.shell.run_cell(b)
finally:
self.shell.using_paste_magics = False
def preclean_input(self, block):
lines = block.splitlines()
while lines and not lines[0].strip():
lines = lines[1:]
return strip_email_quotes('\n'.join(lines))
def rerun_pasted(self, name='pasted_block'):
""" Rerun a previously pasted command.
"""
b = self.shell.user_ns.get(name)
# Sanity checks
if b is None:
raise UsageError('No previous pasted block available')
if not isinstance(b, py3compat.string_types):
raise UsageError(
"Variable 'pasted_block' is not a string, can't execute")
print("Re-executing '%s...' (%d chars)"% (b.split('\n',1)[0], len(b)))
self.shell.run_cell(b)
@line_magic
def autoindent(self, parameter_s = ''):
"""Toggle autoindent on/off (if available)."""
self.shell.set_autoindent()
print("Automatic indentation is:",['OFF','ON'][self.shell.autoindent])
@line_magic
def cpaste(self, parameter_s=''):
"""Paste & execute a pre-formatted code block from clipboard.
You must terminate the block with '--' (two minus-signs) or Ctrl-D
alone on the line. You can also provide your own sentinel with '%paste
-s %%' ('%%' is the new sentinel for this operation).
The block is dedented prior to execution to enable execution of method
definitions. '>' and '+' characters at the beginning of a line are
ignored, to allow pasting directly from e-mails, diff files and
doctests (the '...' continuation prompt is also stripped). The
executed block is also assigned to variable named 'pasted_block' for
later editing with '%edit pasted_block'.
You can also pass a variable name as an argument, e.g. '%cpaste foo'.
This assigns the pasted block to variable 'foo' as string, without
dedenting or executing it (preceding >>> and + is still stripped)
'%cpaste -r' re-executes the block previously entered by cpaste.
'%cpaste -q' suppresses any additional output messages.
Do not be alarmed by garbled output on Windows (it's a readline bug).
Just press enter and type -- (and press enter again) and the block
will be what was just pasted.
IPython statements (magics, shell escapes) are not supported (yet).
See also
--------
paste: automatically pull code from clipboard.
Examples
--------
::
In [8]: %cpaste
Pasting code; enter '--' alone on the line to stop.
:>>> a = ["world!", "Hello"]
:>>> print " ".join(sorted(a))
:--
Hello world!
"""
opts, name = self.parse_options(parameter_s, 'rqs:', mode='string')
if 'r' in opts:
self.rerun_pasted()
return
quiet = ('q' in opts)
sentinel = opts.get('s', u'--')
block = '\n'.join(get_pasted_lines(sentinel, quiet=quiet))
self.store_or_execute(block, name)
@line_magic
def paste(self, parameter_s=''):
"""Paste & execute a pre-formatted code block from clipboard.
The text is pulled directly from the clipboard without user
intervention and printed back on the screen before execution (unless
the -q flag is given to force quiet mode).
The block is dedented prior to execution to enable execution of method
definitions. '>' and '+' characters at the beginning of a line are
ignored, to allow pasting directly from e-mails, diff files and
doctests (the '...' continuation prompt is also stripped). The
executed block is also assigned to variable named 'pasted_block' for
later editing with '%edit pasted_block'.
You can also pass a variable name as an argument, e.g. '%paste foo'.
This assigns the pasted block to variable 'foo' as string, without
executing it (preceding >>> and + is still stripped).
Options:
-r: re-executes the block previously entered by cpaste.
-q: quiet mode: do not echo the pasted text back to the terminal.
IPython statements (magics, shell escapes) are not supported (yet).
See also
--------
cpaste: manually paste code into terminal until you mark its end.
"""
opts, name = self.parse_options(parameter_s, 'rq', mode='string')
if 'r' in opts:
self.rerun_pasted()
return
try:
block = self.shell.hooks.clipboard_get()
except TryNext as clipboard_exc:
message = getattr(clipboard_exc, 'args')
if message:
error(message[0])
else:
error('Could not get text from the clipboard.')
return
except ClipboardEmpty:
raise UsageError("The clipboard appears to be empty")
# By default, echo back to terminal unless quiet mode is requested
if 'q' not in opts:
write = self.shell.write
write(self.shell.pycolorize(block))
if not block.endswith('\n'):
write('\n')
write("## -- End pasted text --\n")
self.store_or_execute(block, name)
# Class-level: add a '%cls' magic only on Windows
if sys.platform == 'win32':
@line_magic
def cls(self, s):
"""Clear screen.
"""
os.system("cls")
class TerminalInteractiveShell(InteractiveShell):
autoedit_syntax = CBool(False, config=True,
help="auto editing of files with syntax errors.")
confirm_exit = CBool(True, config=True,
help="""
Set to confirm when you try to exit IPython with an EOF (Control-D
in Unix, Control-Z/Enter in Windows). By typing 'exit' or 'quit',
you can force a direct exit without any confirmation.""",
)
# This display_banner only controls whether or not self.show_banner()
# is called when mainloop/interact are called. The default is False
# because for the terminal based application, the banner behavior
# is controlled by the application.
display_banner = CBool(False) # This isn't configurable!
embedded = CBool(False)
embedded_active = CBool(False)
editor = Unicode(get_default_editor(), config=True,
help="Set the editor used by IPython (default to $EDITOR/vi/notepad)."
)
pager = Unicode('less', config=True,
help="The shell program to be used for paging.")
screen_length = Integer(0, config=True,
help=
"""Number of lines of your screen, used to control printing of very
long strings. Strings longer than this number of lines will be sent
through a pager instead of directly printed. The default value for
this is 0, which means IPython will auto-detect your screen size every
time it needs to print certain potentially long strings (this doesn't
change the behavior of the 'print' keyword, it's only triggered
internally). If for some reason this isn't working well (it needs
curses support), specify it yourself. Otherwise don't change the
default.""",
)
term_title = CBool(False, config=True,
help="Enable auto setting the terminal title."
)
usage = Unicode(interactive_usage)
# This `using_paste_magics` is used to detect whether the code is being
# executed via paste magics functions
using_paste_magics = CBool(False)
# In the terminal, GUI control is done via PyOS_InputHook
@staticmethod
def enable_gui(gui=None, app=None):
"""Switch amongst GUI input hooks by name.
"""
# Deferred import
from IPython.lib.inputhook import enable_gui as real_enable_gui
try:
return real_enable_gui(gui, app)
except ValueError as e:
raise UsageError("%s" % e)
system = InteractiveShell.system_raw
#-------------------------------------------------------------------------
# Overrides of init stages
#-------------------------------------------------------------------------
def init_display_formatter(self):
super(TerminalInteractiveShell, self).init_display_formatter()
# terminal only supports plaintext
self.display_formatter.active_types = ['text/plain']
#-------------------------------------------------------------------------
# Things related to readline
#-------------------------------------------------------------------------
def init_readline(self):
"""Command history completion/saving/reloading."""
if self.readline_use:
import IPython.utils.rlineimpl as readline
self.rl_next_input = None
self.rl_do_indent = False
if not self.readline_use or not readline.have_readline:
self.readline = None
# Set a number of methods that depend on readline to be no-op
self.readline_no_record = NoOpContext()
self.set_readline_completer = no_op
self.set_custom_completer = no_op
if self.readline_use:
warn('Readline services not available or not loaded.')
else:
self.has_readline = True
self.readline = readline
sys.modules['readline'] = readline
# Platform-specific configuration
if os.name == 'nt':
# FIXME - check with Frederick to see if we can harmonize
# naming conventions with pyreadline to avoid this
# platform-dependent check
self.readline_startup_hook = readline.set_pre_input_hook
else:
self.readline_startup_hook = readline.set_startup_hook
# Readline config order:
# - IPython config (default value)
# - custom inputrc
# - IPython config (user customized)
# load IPython config before inputrc if default
# skip if libedit because parse_and_bind syntax is different
if not self._custom_readline_config and not readline.uses_libedit:
for rlcommand in self.readline_parse_and_bind:
readline.parse_and_bind(rlcommand)
# Load user's initrc file (readline config)
# Or if libedit is used, load editrc.
inputrc_name = os.environ.get('INPUTRC')
if inputrc_name is None:
inputrc_name = '.inputrc'
if readline.uses_libedit:
inputrc_name = '.editrc'
inputrc_name = os.path.join(self.home_dir, inputrc_name)
if os.path.isfile(inputrc_name):
try:
readline.read_init_file(inputrc_name)
except:
warn('Problems reading readline initialization file <%s>'
% inputrc_name)
# load IPython config after inputrc if user has customized
if self._custom_readline_config:
for rlcommand in self.readline_parse_and_bind:
readline.parse_and_bind(rlcommand)
# Remove some chars from the delimiters list. If we encounter
# unicode chars, discard them.
delims = readline.get_completer_delims()
if not py3compat.PY3:
delims = delims.encode("ascii", "ignore")
for d in self.readline_remove_delims:
delims = delims.replace(d, "")
delims = delims.replace(ESC_MAGIC, '')
readline.set_completer_delims(delims)
# Store these so we can restore them if something like rpy2 modifies
# them.
self.readline_delims = delims
# otherwise we end up with a monster history after a while:
readline.set_history_length(self.history_length)
self.refill_readline_hist()
self.readline_no_record = ReadlineNoRecord(self)
# Configure auto-indent for all platforms
self.set_autoindent(self.autoindent)
def init_completer(self):
super(TerminalInteractiveShell, self).init_completer()
# Only configure readline if we truly are using readline.
if self.has_readline:
self.set_readline_completer()
def set_readline_completer(self):
"""Reset readline's completer to be our own."""
self.readline.set_completer(self.Completer.rlcomplete)
def pre_readline(self):
"""readline hook to be used at the start of each line.
It handles auto-indent and text from set_next_input."""
if self.rl_do_indent:
self.readline.insert_text(self._indent_current_str())
if self.rl_next_input is not None:
self.readline.insert_text(self.rl_next_input)
self.rl_next_input = None
def refill_readline_hist(self):
# Load the last 1000 lines from history
self.readline.clear_history()
stdin_encoding = sys.stdin.encoding or "utf-8"
last_cell = u""
for _, _, cell in self.history_manager.get_tail(self.history_load_length,
include_latest=True):
# Ignore blank lines and consecutive duplicates
cell = cell.rstrip()
if cell and (cell != last_cell):
try:
if self.multiline_history:
self.readline.add_history(py3compat.unicode_to_str(cell,
stdin_encoding))
else:
for line in cell.splitlines():
self.readline.add_history(py3compat.unicode_to_str(line,
stdin_encoding))
last_cell = cell
except TypeError:
# The history DB can get corrupted so it returns strings
# containing null bytes, which readline objects to.
continue
#-------------------------------------------------------------------------
# Things related to the terminal
#-------------------------------------------------------------------------
@property
def usable_screen_length(self):
if self.screen_length == 0:
return 0
else:
num_lines_bot = self.separate_in.count('\n')+1
return self.screen_length - num_lines_bot
def _term_title_changed(self, name, new_value):
self.init_term_title()
def init_term_title(self):
# Enable or disable the terminal title.
if self.term_title:
toggle_set_term_title(True)
set_term_title('IPython: ' + abbrev_cwd())
else:
toggle_set_term_title(False)
#-------------------------------------------------------------------------
# Things related to aliases
#-------------------------------------------------------------------------
def init_alias(self):
# The parent class defines aliases that can be safely used with any
# frontend.
super(TerminalInteractiveShell, self).init_alias()
# Now define aliases that only make sense on the terminal, because they
# need direct access to the console in a way that we can't emulate in
# GUI or web frontend
if os.name == 'posix':
aliases = [('clear', 'clear'), ('more', 'more'), ('less', 'less'),
('man', 'man')]
else :
aliases = []
for name, cmd in aliases:
self.alias_manager.soft_define_alias(name, cmd)
#-------------------------------------------------------------------------
# Mainloop and code execution logic
#-------------------------------------------------------------------------
def mainloop(self, display_banner=None):
"""Start the mainloop.
If an optional banner argument is given, it will override the
internally created default banner.
"""
with self.builtin_trap, self.display_trap:
while 1:
try:
self.interact(display_banner=display_banner)
#self.interact_with_readline()
# XXX for testing of a readline-decoupled repl loop, call
# interact_with_readline above
break
except KeyboardInterrupt:
# this should not be necessary, but KeyboardInterrupt
# handling seems rather unpredictable...
self.write("\nKeyboardInterrupt in interact()\n")
def _replace_rlhist_multiline(self, source_raw, hlen_before_cell):
"""Store multiple lines as a single entry in history"""
# do nothing without readline or disabled multiline
if not self.has_readline or not self.multiline_history:
return hlen_before_cell
# windows rl has no remove_history_item
if not hasattr(self.readline, "remove_history_item"):
return hlen_before_cell
# skip empty cells
if not source_raw.rstrip():
return hlen_before_cell
# nothing changed do nothing, e.g. when rl removes consecutive dups
hlen = self.readline.get_current_history_length()
if hlen == hlen_before_cell:
return hlen_before_cell
for i in range(hlen - hlen_before_cell):
self.readline.remove_history_item(hlen - i - 1)
stdin_encoding = get_stream_enc(sys.stdin, 'utf-8')
self.readline.add_history(py3compat.unicode_to_str(source_raw.rstrip(),
stdin_encoding))
return self.readline.get_current_history_length()
def interact(self, display_banner=None):
"""Closely emulate the interactive Python console."""
# batch run -> do not interact
if self.exit_now:
return
if display_banner is None:
display_banner = self.display_banner
if isinstance(display_banner, py3compat.string_types):
self.show_banner(display_banner)
elif display_banner:
self.show_banner()
more = False
if self.has_readline:
self.readline_startup_hook(self.pre_readline)
hlen_b4_cell = self.readline.get_current_history_length()
else:
hlen_b4_cell = 0
# exit_now is set by a call to %Exit or %Quit, through the
# ask_exit callback.
while not self.exit_now:
self.hooks.pre_prompt_hook()
if more:
try:
prompt = self.prompt_manager.render('in2')
except:
self.showtraceback()
if self.autoindent:
self.rl_do_indent = True
else:
try:
prompt = self.separate_in + self.prompt_manager.render('in')
except:
self.showtraceback()
try:
line = self.raw_input(prompt)
if self.exit_now:
# quick exit on sys.std[in|out] close
break
if self.autoindent:
self.rl_do_indent = False
except KeyboardInterrupt:
#double-guard against keyboardinterrupts during kbdint handling
try:
self.write('\n' + self.get_exception_only())
source_raw = self.input_splitter.raw_reset()
hlen_b4_cell = \
self._replace_rlhist_multiline(source_raw, hlen_b4_cell)
more = False
except KeyboardInterrupt:
pass
except EOFError:
if self.autoindent:
self.rl_do_indent = False
if self.has_readline:
self.readline_startup_hook(None)
self.write('\n')
self.exit()
except bdb.BdbQuit:
warn('The Python debugger has exited with a BdbQuit exception.\n'
'Because of how pdb handles the stack, it is impossible\n'
'for IPython to properly format this particular exception.\n'
'IPython will resume normal operation.')
except:
# exceptions here are VERY RARE, but they can be triggered
# asynchronously by signal handlers, for example.
self.showtraceback()
else:
try:
self.input_splitter.push(line)
more = self.input_splitter.push_accepts_more()
except SyntaxError:
# Run the code directly - run_cell takes care of displaying
# the exception.
more = False
if (self.SyntaxTB.last_syntax_error and
self.autoedit_syntax):
self.edit_syntax_error()
if not more:
source_raw = self.input_splitter.raw_reset()
self.run_cell(source_raw, store_history=True)
hlen_b4_cell = \
self._replace_rlhist_multiline(source_raw, hlen_b4_cell)
# Turn off the exit flag, so the mainloop can be restarted if desired
self.exit_now = False
def raw_input(self, prompt=''):
"""Write a prompt and read a line.
The returned line does not include the trailing newline.
When the user enters the EOF key sequence, EOFError is raised.
Parameters
----------
prompt : str, optional
A string to be printed to prompt the user.
"""
# raw_input expects str, but we pass it unicode sometimes
prompt = py3compat.cast_bytes_py2(prompt)
try:
line = py3compat.cast_unicode_py2(self.raw_input_original(prompt))
except ValueError:
warn("\n********\nYou or a %run:ed script called sys.stdin.close()"
" or sys.stdout.close()!\nExiting IPython!\n")
self.ask_exit()
return ""
# Try to be reasonably smart about not re-indenting pasted input more
# than necessary. We do this by trimming out the auto-indent initial
# spaces, if the user's actual input started itself with whitespace.
if self.autoindent:
if num_ini_spaces(line) > self.indent_current_nsp:
line = line[self.indent_current_nsp:]
self.indent_current_nsp = 0
return line
#-------------------------------------------------------------------------
# Methods to support auto-editing of SyntaxErrors.
#-------------------------------------------------------------------------
def edit_syntax_error(self):
"""The bottom half of the syntax error handler called in the main loop.
Loop until syntax error is fixed or user cancels.
"""
while self.SyntaxTB.last_syntax_error:
# copy and clear last_syntax_error
err = self.SyntaxTB.clear_err_state()
if not self._should_recompile(err):
return
try:
# may set last_syntax_error again if a SyntaxError is raised
self.safe_execfile(err.filename,self.user_ns)
except:
self.showtraceback()
else:
try:
f = open(err.filename)
try:
# This should be inside a display_trap block and I
# think it is.
sys.displayhook(f.read())
finally:
f.close()
except:
self.showtraceback()
def _should_recompile(self,e):
"""Utility routine for edit_syntax_error"""
if e.filename in ('<ipython console>','<input>','<string>',
'<console>','<BackgroundJob compilation>',
None):
return False
try:
if (self.autoedit_syntax and
not self.ask_yes_no('Return to editor to correct syntax error? '
'[Y/n] ','y')):
return False
except EOFError:
return False
def int0(x):
try:
return int(x)
except TypeError:
return 0
# always pass integer line and offset values to editor hook
try:
self.hooks.fix_error_editor(e.filename,
int0(e.lineno),int0(e.offset),e.msg)
except TryNext:
warn('Could not open editor')
return False
return True
#-------------------------------------------------------------------------
# Things related to exiting
#-------------------------------------------------------------------------
def ask_exit(self):
""" Ask the shell to exit. Can be overiden and used as a callback. """
self.exit_now = True
def exit(self):
"""Handle interactive exit.
This method calls the ask_exit callback."""
if self.confirm_exit:
if self.ask_yes_no('Do you really want to exit ([y]/n)?','y','n'):
self.ask_exit()
else:
self.ask_exit()
#-------------------------------------------------------------------------
# Things related to magics
#-------------------------------------------------------------------------
def init_magics(self):
super(TerminalInteractiveShell, self).init_magics()
self.register_magics(TerminalMagics)
def showindentationerror(self):
super(TerminalInteractiveShell, self).showindentationerror()
if not self.using_paste_magics:
print("If you want to paste code into IPython, try the "
"%paste and %cpaste magic functions.")
InteractiveShellABC.register(TerminalInteractiveShell)