Note use of -- for -i to behave like cpython

Providing script arguments is only really useful with -i, and while this is described in the main Usage section of ipython --help, it seems more directly helpful here

IPython/terminal/ipapp.py

@@ -1,374 +1,377 b''
 #!/usr/bin/env python
 # encoding: utf-8
 """
 The :class:`~IPython.core.application.Application` object for the command
 line :command:`ipython` program.
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 from __future__ import absolute_import
 from __future__ import print_function
 
 import logging
 import os
 import sys
 
 from traitlets.config.loader import Config
 from traitlets.config.application import boolean_flag, catch_config_error, Application
 from IPython.core import release
 from IPython.core import usage
 from IPython.core.completer import IPCompleter
 from IPython.core.crashhandler import CrashHandler
 from IPython.core.formatters import PlainTextFormatter
 from IPython.core.history import HistoryManager
 from IPython.core.prompts import PromptManager
 from IPython.core.application import (
     ProfileDir, BaseIPythonApplication, base_flags, base_aliases
 )
 from IPython.core.magics import ScriptMagics
 from IPython.core.shellapp import (
     InteractiveShellApp, shell_flags, shell_aliases
 )
 from IPython.extensions.storemagic import StoreMagics
 from IPython.terminal.interactiveshell import TerminalInteractiveShell
 from IPython.utils import warn
 from IPython.paths import get_ipython_dir
 from traitlets import (
     Bool, List, Dict,
 )
 
 #-----------------------------------------------------------------------------
 # Globals, utilities and helpers
 #-----------------------------------------------------------------------------
 
 _examples = """
 ipython --matplotlib       # enable matplotlib integration
 ipython --matplotlib=qt    # enable matplotlib integration with qt4 backend
 
 ipython --log-level=DEBUG  # set logging to DEBUG
 ipython --profile=foo      # start with profile foo
 
 ipython qtconsole          # start the qtconsole GUI application
 ipython help qtconsole     # show the help for the qtconsole subcmd
 
 ipython console            # start the terminal-based console application
 ipython help console       # show the help for the console subcmd
 
 ipython notebook           # start the IPython notebook
 ipython help notebook      # show the help for the notebook subcmd
 
 ipython profile create foo # create profile foo w/ default config files
 ipython help profile       # show the help for the profile subcmd
 
 ipython locate             # print the path to the IPython directory
 ipython locate profile foo # print the path to the directory for profile `foo`
 
 ipython nbconvert           # convert notebooks to/from other formats
 """
 
 #-----------------------------------------------------------------------------
 # Crash handler for this application
 #-----------------------------------------------------------------------------
 
 class IPAppCrashHandler(CrashHandler):
     """sys.excepthook for IPython itself, leaves a detailed report on disk."""
 
     def __init__(self, app):
         contact_name = release.author
         contact_email = release.author_email
         bug_tracker = 'https://github.com/ipython/ipython/issues'
         super(IPAppCrashHandler,self).__init__(
             app, contact_name, contact_email, bug_tracker
         )
 
     def make_report(self,traceback):
         """Return a string containing a crash report."""
 
         sec_sep = self.section_sep
         # Start with parent report
         report = [super(IPAppCrashHandler, self).make_report(traceback)]
         # Add interactive-specific info we may have
         rpt_add = report.append
         try:
             rpt_add(sec_sep+"History of session input:")
             for line in self.app.shell.user_ns['_ih']:
                 rpt_add(line)
             rpt_add('\n*** Last line of input (may not be in above history):\n')
             rpt_add(self.app.shell._last_input_line+'\n')
         except:
             pass
 
         return ''.join(report)
 
 #-----------------------------------------------------------------------------
 # Aliases and Flags
 #-----------------------------------------------------------------------------
 flags = dict(base_flags)
 flags.update(shell_flags)
 frontend_flags = {}
 addflag = lambda *args: frontend_flags.update(boolean_flag(*args))
 addflag('autoedit-syntax', 'TerminalInteractiveShell.autoedit_syntax',
         'Turn on auto editing of files with syntax errors.',
         'Turn off auto editing of files with syntax errors.'
 )
 addflag('banner', 'TerminalIPythonApp.display_banner',
         "Display a banner upon starting IPython.",
         "Don't display a banner upon starting IPython."
 )
 addflag('confirm-exit', 'TerminalInteractiveShell.confirm_exit',
     """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.""",
     "Don't prompt the user when exiting."
 )
 addflag('term-title', 'TerminalInteractiveShell.term_title',
     "Enable auto setting the terminal title.",
     "Disable auto setting the terminal title."
 )
 classic_config = Config()
 classic_config.InteractiveShell.cache_size = 0
 classic_config.PlainTextFormatter.pprint = False
 classic_config.PromptManager.in_template = '>>> '
 classic_config.PromptManager.in2_template = '... '
 classic_config.PromptManager.out_template = ''
 classic_config.InteractiveShell.separate_in = ''
 classic_config.InteractiveShell.separate_out = ''
 classic_config.InteractiveShell.separate_out2 = ''
 classic_config.InteractiveShell.colors = 'NoColor'
 classic_config.InteractiveShell.xmode = 'Plain'
 
 frontend_flags['classic']=(
     classic_config,
     "Gives IPython a similar feel to the classic Python prompt."
 )
 # # log doesn't make so much sense this way anymore
 # paa('--log','-l',
 #     action='store_true', dest='InteractiveShell.logstart',
 #     help="Start logging to the default log file (./ipython_log.py).")
 #
 # # quick is harder to implement
 frontend_flags['quick']=(
     {'TerminalIPythonApp' : {'quick' : True}},
     "Enable quick startup with no config files."
 )
 
 frontend_flags['i'] = (
     {'TerminalIPythonApp' : {'force_interact' : True}},
-    """If running code from the command line, become interactive afterwards."""
+    """If running code from the command line, become interactive afterwards.
+    It is often useful to follow this with `--` to treat remaining flags as
+    script arguments.
+    """
 )
 flags.update(frontend_flags)
 
 aliases = dict(base_aliases)
 aliases.update(shell_aliases)
 
 #-----------------------------------------------------------------------------
 # Main classes and functions
 #-----------------------------------------------------------------------------
 
 
 class LocateIPythonApp(BaseIPythonApplication):
     description = """print the path to the IPython dir"""
     subcommands = Dict(dict(
         profile=('IPython.core.profileapp.ProfileLocate',
             "print the path to an IPython profile directory",
         ),
     ))
     def start(self):
         if self.subapp is not None:
             return self.subapp.start()
         else:
             print(self.ipython_dir)
 
 
 class TerminalIPythonApp(BaseIPythonApplication, InteractiveShellApp):
     name = u'ipython'
     description = usage.cl_usage
     crash_handler_class = IPAppCrashHandler
     examples = _examples
 
     flags = Dict(flags)
     aliases = Dict(aliases)
     classes = List()
     def _classes_default(self):
         """This has to be in a method, for TerminalIPythonApp to be available."""
         return [
             InteractiveShellApp, # ShellApp comes before TerminalApp, because
             self.__class__,      # it will also affect subclasses (e.g. QtConsole)
             TerminalInteractiveShell,
             PromptManager,
             HistoryManager,
             ProfileDir,
             PlainTextFormatter,
             IPCompleter,
             ScriptMagics,
             StoreMagics,
         ]
 
     subcommands = dict(
         qtconsole=('qtconsole.qtconsoleapp.JupyterQtConsoleApp',
             """DEPRECATD: Launch the Jupyter Qt Console."""
         ),
         notebook=('notebook.notebookapp.NotebookApp',
             """DEPRECATED: Launch the Jupyter HTML Notebook Server."""
         ),
         profile = ("IPython.core.profileapp.ProfileApp",
             "Create and manage IPython profiles."
         ),
         kernel = ("ipykernel.kernelapp.IPKernelApp",
             "Start a kernel without an attached frontend."
         ),
         console=('jupyter_console.app.ZMQTerminalIPythonApp',
             """DEPRECATED: Launch the Jupyter terminal-based Console."""
         ),
         locate=('IPython.terminal.ipapp.LocateIPythonApp',
             LocateIPythonApp.description
         ),
         history=('IPython.core.historyapp.HistoryApp',
             "Manage the IPython history database."
         ),
         nbconvert=('nbconvert.nbconvertapp.NbConvertApp',
             "DEPRECATED: Convert notebooks to/from other formats."
         ),
         trust=('nbformat.sign.TrustNotebookApp',
             "DEPRECATED: Sign notebooks to trust their potentially unsafe contents at load."
         ),
         kernelspec=('jupyter_client.kernelspecapp.KernelSpecApp',
             "DEPRECATED: Manage Jupyter kernel specifications."
         ),
     )
     subcommands['install-nbextension'] = (
         "notebook.nbextensions.InstallNBExtensionApp",
         "DEPRECATED: Install Jupyter notebook extension files"
     )
 
     # *do* autocreate requested profile, but don't create the config file.
     auto_create=Bool(True)
     # configurables
     quick = Bool(False, config=True,
         help="""Start IPython quickly by skipping the loading of config files."""
     )
     def _quick_changed(self, name, old, new):
         if new:
             self.load_config_file = lambda *a, **kw: None
 
     display_banner = Bool(True, config=True,
         help="Whether to display a banner upon starting IPython."
     )
 
     # if there is code of files to run from the cmd line, don't interact
     # unless the --i flag (App.force_interact) is true.
     force_interact = Bool(False, config=True,
         help="""If a command or file is given via the command-line,
         e.g. 'ipython foo.py', start an interactive shell after executing the
         file or command."""
     )
     def _force_interact_changed(self, name, old, new):
         if new:
             self.interact = True
 
     def _file_to_run_changed(self, name, old, new):
         if new:
             self.something_to_run = True
         if new and not self.force_interact:
                 self.interact = False
     _code_to_run_changed = _file_to_run_changed
     _module_to_run_changed = _file_to_run_changed
 
     # internal, not-configurable
     interact=Bool(True)
     something_to_run=Bool(False)
 
     def parse_command_line(self, argv=None):
         """override to allow old '-pylab' flag with deprecation warning"""
 
         argv = sys.argv[1:] if argv is None else argv
 
         if '-pylab' in argv:
             # deprecated `-pylab` given,
             # warn and transform into current syntax
             argv = argv[:] # copy, don't clobber
             idx = argv.index('-pylab')
             warn.warn("`-pylab` flag has been deprecated.\n"
             "    Use `--matplotlib <backend>` and import pylab manually.")
             argv[idx] = '--pylab'
 
         return super(TerminalIPythonApp, self).parse_command_line(argv)
     
     @catch_config_error
     def initialize(self, argv=None):
         """Do actions after construct, but before starting the app."""
         super(TerminalIPythonApp, self).initialize(argv)
         if self.subapp is not None:
             # don't bother initializing further, starting subapp
             return
         # print self.extra_args
         if self.extra_args and not self.something_to_run:
             self.file_to_run = self.extra_args[0]
         self.init_path()
         # create the shell
         self.init_shell()
         # and draw the banner
         self.init_banner()
         # Now a variety of things that happen after the banner is printed.
         self.init_gui_pylab()
         self.init_extensions()
         self.init_code()
 
     def init_shell(self):
         """initialize the InteractiveShell instance"""
         # Create an InteractiveShell instance.
         # shell.display_banner should always be False for the terminal
         # based app, because we call shell.show_banner() by hand below
         # so the banner shows *before* all extension loading stuff.
         self.shell = TerminalInteractiveShell.instance(parent=self,
                         display_banner=False, profile_dir=self.profile_dir,
                         ipython_dir=self.ipython_dir, user_ns=self.user_ns)
         self.shell.configurables.append(self)
 
     def init_banner(self):
         """optionally display the banner"""
         if self.display_banner and self.interact:
             self.shell.show_banner()
         # Make sure there is a space below the banner.
         if self.log_level <= logging.INFO: print()
 
     def _pylab_changed(self, name, old, new):
         """Replace --pylab='inline' with --pylab='auto'"""
         if new == 'inline':
             warn.warn("'inline' not available as pylab backend, "
                       "using 'auto' instead.")
             self.pylab = 'auto'
 
     def start(self):
         if self.subapp is not None:
             return self.subapp.start()
         # perform any prexec steps:
         if self.interact:
             self.log.debug("Starting IPython's mainloop...")
             self.shell.mainloop()
         else:
             self.log.debug("IPython not interactive...")
 
 def load_default_config(ipython_dir=None):
     """Load the default config file from the default ipython_dir.
 
     This is useful for embedded shells.
     """
     if ipython_dir is None:
         ipython_dir = get_ipython_dir()
 
     profile_dir = os.path.join(ipython_dir, 'profile_default')
 
     config = Config()
     for cf in Application._load_config_files("ipython_config", path=profile_dir):
         config.update(cf)
 
     return config
 
 launch_new_instance = TerminalIPythonApp.launch_instance
 
 
 if __name__ == '__main__':
     launch_new_instance()