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# encoding: utf-8
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"""A base class for a configurable application."""
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# Copyright (c) IPython Development Team.
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# Distributed under the terms of the Modified BSD License.
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from __future__ import print_function
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import json
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import logging
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import os
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import re
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import sys
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from copy import deepcopy
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from collections import defaultdict
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from IPython.external.decorator import decorator
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from IPython.config.configurable import SingletonConfigurable
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from IPython.config.loader import (
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KVArgParseConfigLoader, PyFileConfigLoader, Config, ArgumentError, ConfigFileNotFound, JSONFileConfigLoader
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)
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from IPython.utils.traitlets import (
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Unicode, List, Enum, Dict, Instance, TraitError
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)
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from IPython.utils.importstring import import_item
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from IPython.utils.text import indent, wrap_paragraphs, dedent
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from IPython.utils import py3compat
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from IPython.utils.py3compat import string_types, iteritems
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#-----------------------------------------------------------------------------
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# Descriptions for the various sections
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#-----------------------------------------------------------------------------
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# merge flags&aliases into options
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option_description = """
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Arguments that take values are actually convenience aliases to full
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Configurables, whose aliases are listed on the help line. For more information
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on full configurables, see '--help-all'.
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""".strip() # trim newlines of front and back
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keyvalue_description = """
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Parameters are set from command-line arguments of the form:
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`--Class.trait=value`.
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This line is evaluated in Python, so simple expressions are allowed, e.g.::
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`--C.a='range(3)'` For setting C.a=[0,1,2].
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""".strip() # trim newlines of front and back
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# sys.argv can be missing, for example when python is embedded. See the docs
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# for details: http://docs.python.org/2/c-api/intro.html#embedding-python
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if not hasattr(sys, "argv"):
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sys.argv = [""]
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subcommand_description = """
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Subcommands are launched as `{app} cmd [args]`. For information on using
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subcommand 'cmd', do: `{app} cmd -h`.
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"""
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# get running program name
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#-----------------------------------------------------------------------------
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# Application class
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#-----------------------------------------------------------------------------
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@decorator
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def catch_config_error(method, app, *args, **kwargs):
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"""Method decorator for catching invalid config (Trait/ArgumentErrors) during init.
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On a TraitError (generally caused by bad config), this will print the trait's
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message, and exit the app.
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For use on init methods, to prevent invoking excepthook on invalid input.
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"""
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try:
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return method(app, *args, **kwargs)
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except (TraitError, ArgumentError) as e:
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app.print_help()
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app.log.fatal("Bad config encountered during initialization:")
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app.log.fatal(str(e))
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app.log.debug("Config at the time: %s", app.config)
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app.exit(1)
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class ApplicationError(Exception):
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pass
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class LevelFormatter(logging.Formatter):
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"""Formatter with additional `highlevel` record
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This field is empty if log level is less than highlevel_limit,
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otherwise it is formatted with self.highlevel_format.
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Useful for adding 'WARNING' to warning messages,
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without adding 'INFO' to info, etc.
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"""
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highlevel_limit = logging.WARN
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highlevel_format = " %(levelname)s |"
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def format(self, record):
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if record.levelno >= self.highlevel_limit:
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record.highlevel = self.highlevel_format % record.__dict__
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else:
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record.highlevel = ""
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return super(LevelFormatter, self).format(record)
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class Application(SingletonConfigurable):
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"""A singleton application with full configuration support."""
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# The name of the application, will usually match the name of the command
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# line application
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name = Unicode(u'application')
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# The description of the application that is printed at the beginning
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# of the help.
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description = Unicode(u'This is an application.')
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# default section descriptions
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option_description = Unicode(option_description)
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keyvalue_description = Unicode(keyvalue_description)
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subcommand_description = Unicode(subcommand_description)
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# The usage and example string that goes at the end of the help string.
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examples = Unicode()
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# A sequence of Configurable subclasses whose config=True attributes will
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# be exposed at the command line.
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classes = []
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@property
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def _help_classes(self):
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"""Define `App.help_classes` if CLI classes should differ from config file classes"""
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return getattr(self, 'help_classes', self.classes)
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@property
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def _config_classes(self):
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"""Define `App.config_classes` if config file classes should differ from CLI classes."""
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return getattr(self, 'config_classes', self.classes)
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# The version string of this application.
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version = Unicode(u'0.0')
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# the argv used to initialize the application
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argv = List()
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# The log level for the application
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log_level = Enum((0,10,20,30,40,50,'DEBUG','INFO','WARN','ERROR','CRITICAL'),
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default_value=logging.WARN,
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config=True,
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help="Set the log level by value or name.")
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def _log_level_changed(self, name, old, new):
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"""Adjust the log level when log_level is set."""
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if isinstance(new, string_types):
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new = getattr(logging, new)
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self.log_level = new
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self.log.setLevel(new)
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_log_formatter_cls = LevelFormatter
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log_datefmt = Unicode("%Y-%m-%d %H:%M:%S", config=True,
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help="The date format used by logging formatters for %(asctime)s"
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)
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def _log_datefmt_changed(self, name, old, new):
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self._log_format_changed()
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log_format = Unicode("[%(name)s]%(highlevel)s %(message)s", config=True,
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help="The Logging format template",
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)
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def _log_format_changed(self, name, old, new):
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"""Change the log formatter when log_format is set."""
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_log_handler = self.log.handlers[0]
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_log_formatter = self._log_formatter_cls(fmt=new, datefmt=self.log_datefmt)
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_log_handler.setFormatter(_log_formatter)
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log = Instance(logging.Logger)
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def _log_default(self):
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"""Start logging for this application.
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The default is to log to stderr using a StreamHandler, if no default
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handler already exists. The log level starts at logging.WARN, but this
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can be adjusted by setting the ``log_level`` attribute.
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"""
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log = logging.getLogger(self.__class__.__name__)
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log.setLevel(self.log_level)
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log.propagate = False
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_log = log # copied from Logger.hasHandlers() (new in Python 3.2)
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while _log:
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if _log.handlers:
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return log
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if not _log.propagate:
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break
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else:
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_log = _log.parent
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if sys.executable.endswith('pythonw.exe'):
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# this should really go to a file, but file-logging is only
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# hooked up in parallel applications
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_log_handler = logging.StreamHandler(open(os.devnull, 'w'))
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else:
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_log_handler = logging.StreamHandler()
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_log_formatter = self._log_formatter_cls(fmt=self.log_format, datefmt=self.log_datefmt)
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_log_handler.setFormatter(_log_formatter)
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log.addHandler(_log_handler)
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return log
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# the alias map for configurables
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aliases = Dict({'log-level' : 'Application.log_level'})
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# flags for loading Configurables or store_const style flags
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# flags are loaded from this dict by '--key' flags
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# this must be a dict of two-tuples, the first element being the Config/dict
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# and the second being the help string for the flag
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flags = Dict()
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def _flags_changed(self, name, old, new):
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"""ensure flags dict is valid"""
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for key,value in iteritems(new):
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assert len(value) == 2, "Bad flag: %r:%s"%(key,value)
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assert isinstance(value[0], (dict, Config)), "Bad flag: %r:%s"%(key,value)
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assert isinstance(value[1], string_types), "Bad flag: %r:%s"%(key,value)
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# subcommands for launching other applications
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# if this is not empty, this will be a parent Application
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# this must be a dict of two-tuples,
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# the first element being the application class/import string
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# and the second being the help string for the subcommand
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subcommands = Dict()
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# parse_command_line will initialize a subapp, if requested
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subapp = Instance('IPython.config.application.Application', allow_none=True)
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# extra command-line arguments that don't set config values
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extra_args = List(Unicode)
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def __init__(self, **kwargs):
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SingletonConfigurable.__init__(self, **kwargs)
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# Ensure my class is in self.classes, so my attributes appear in command line
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# options and config files.
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if self.__class__ not in self.classes:
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self.classes.insert(0, self.__class__)
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def _config_changed(self, name, old, new):
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SingletonConfigurable._config_changed(self, name, old, new)
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self.log.debug('Config changed:')
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self.log.debug(repr(new))
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@catch_config_error
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def initialize(self, argv=None):
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"""Do the basic steps to configure me.
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Override in subclasses.
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"""
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self.parse_command_line(argv)
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def start(self):
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"""Start the app mainloop.
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Override in subclasses.
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"""
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if self.subapp is not None:
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return self.subapp.start()
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def print_alias_help(self):
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"""Print the alias part of the help."""
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if not self.aliases:
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return
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lines = []
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classdict = {}
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for cls in self._help_classes:
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# include all parents (up to, but excluding Configurable) in available names
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for c in cls.mro()[:-3]:
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classdict[c.__name__] = c
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for alias, longname in iteritems(self.aliases):
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classname, traitname = longname.split('.',1)
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cls = classdict[classname]
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trait = cls.class_traits(config=True)[traitname]
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help = cls.class_get_trait_help(trait).splitlines()
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# reformat first line
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help[0] = help[0].replace(longname, alias) + ' (%s)'%longname
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if len(alias) == 1:
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help[0] = help[0].replace('--%s='%alias, '-%s '%alias)
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lines.extend(help)
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# lines.append('')
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print(os.linesep.join(lines))
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def print_flag_help(self):
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"""Print the flag part of the help."""
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if not self.flags:
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return
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lines = []
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for m, (cfg,help) in iteritems(self.flags):
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prefix = '--' if len(m) > 1 else '-'
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lines.append(prefix+m)
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lines.append(indent(dedent(help.strip())))
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# lines.append('')
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print(os.linesep.join(lines))
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def print_options(self):
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if not self.flags and not self.aliases:
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return
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lines = ['Options']
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lines.append('-'*len(lines[0]))
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lines.append('')
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for p in wrap_paragraphs(self.option_description):
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lines.append(p)
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lines.append('')
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print(os.linesep.join(lines))
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self.print_flag_help()
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self.print_alias_help()
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print()
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def print_subcommands(self):
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"""Print the subcommand part of the help."""
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if not self.subcommands:
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return
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lines = ["Subcommands"]
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lines.append('-'*len(lines[0]))
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lines.append('')
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for p in wrap_paragraphs(self.subcommand_description.format(
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app=self.name)):
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lines.append(p)
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lines.append('')
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for subc, (cls, help) in iteritems(self.subcommands):
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lines.append(subc)
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if help:
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lines.append(indent(dedent(help.strip())))
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lines.append('')
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print(os.linesep.join(lines))
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def print_help(self, classes=False):
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"""Print the help for each Configurable class in self.classes.
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If classes=False (the default), only flags and aliases are printed.
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"""
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self.print_description()
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self.print_subcommands()
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self.print_options()
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if classes:
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help_classes = self._help_classes
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if help_classes:
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print("Class parameters")
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print("----------------")
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print()
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for p in wrap_paragraphs(self.keyvalue_description):
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print(p)
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print()
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for cls in help_classes:
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cls.class_print_help()
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print()
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else:
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print("To see all available configurables, use `--help-all`")
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print()
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self.print_examples()
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def print_description(self):
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"""Print the application description."""
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for p in wrap_paragraphs(self.description):
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print(p)
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print()
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def print_examples(self):
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"""Print usage and examples.
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This usage string goes at the end of the command line help string
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and should contain examples of the application's usage.
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"""
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if self.examples:
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print("Examples")
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print("--------")
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print()
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print(indent(dedent(self.examples.strip())))
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print()
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def print_version(self):
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"""Print the version string."""
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print(self.version)
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def update_config(self, config):
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"""Fire the traits events when the config is updated."""
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# Save a copy of the current config.
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newconfig = deepcopy(self.config)
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# Merge the new config into the current one.
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newconfig.merge(config)
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# Save the combined config as self.config, which triggers the traits
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# events.
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self.config = newconfig
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@catch_config_error
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def initialize_subcommand(self, subc, argv=None):
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"""Initialize a subcommand with argv."""
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subapp,help = self.subcommands.get(subc)
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if isinstance(subapp, string_types):
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subapp = import_item(subapp)
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# clear existing instances
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self.__class__.clear_instance()
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# instantiate
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self.subapp = subapp.instance(config=self.config)
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# and initialize subapp
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self.subapp.initialize(argv)
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def flatten_flags(self):
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"""flatten flags and aliases, so cl-args override as expected.
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This prevents issues such as an alias pointing to InteractiveShell,
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but a config file setting the same trait in TerminalInteraciveShell
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getting inappropriate priority over the command-line arg.
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Only aliases with exactly one descendent in the class list
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will be promoted.
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"""
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# build a tree of classes in our list that inherit from a particular
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# it will be a dict by parent classname of classes in our list
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# that are descendents
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mro_tree = defaultdict(list)
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for cls in self._help_classes:
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clsname = cls.__name__
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for parent in cls.mro()[1:-3]:
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# exclude cls itself and Configurable,HasTraits,object
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mro_tree[parent.__name__].append(clsname)
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# flatten aliases, which have the form:
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# { 'alias' : 'Class.trait' }
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aliases = {}
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for alias, cls_trait in iteritems(self.aliases):
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cls,trait = cls_trait.split('.',1)
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children = mro_tree[cls]
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if len(children) == 1:
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# exactly one descendent, promote alias
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cls = children[0]
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aliases[alias] = '.'.join([cls,trait])
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|
|
|
# flatten flags, which are of the form:
|
|
|
# { 'key' : ({'Cls' : {'trait' : value}}, 'help')}
|
|
|
flags = {}
|
|
|
for key, (flagdict, help) in iteritems(self.flags):
|
|
|
newflag = {}
|
|
|
for cls, subdict in iteritems(flagdict):
|
|
|
children = mro_tree[cls]
|
|
|
# exactly one descendent, promote flag section
|
|
|
if len(children) == 1:
|
|
|
cls = children[0]
|
|
|
newflag[cls] = subdict
|
|
|
flags[key] = (newflag, help)
|
|
|
return flags, aliases
|
|
|
|
|
|
@catch_config_error
|
|
|
def parse_command_line(self, argv=None):
|
|
|
"""Parse the command line arguments."""
|
|
|
argv = sys.argv[1:] if argv is None else argv
|
|
|
self.argv = [ py3compat.cast_unicode(arg) for arg in argv ]
|
|
|
|
|
|
if argv and argv[0] == 'help':
|
|
|
# turn `ipython help notebook` into `ipython notebook -h`
|
|
|
argv = argv[1:] + ['-h']
|
|
|
|
|
|
if self.subcommands and len(argv) > 0:
|
|
|
# we have subcommands, and one may have been specified
|
|
|
subc, subargv = argv[0], argv[1:]
|
|
|
if re.match(r'^\w(\-?\w)*$', subc) and subc in self.subcommands:
|
|
|
# it's a subcommand, and *not* a flag or class parameter
|
|
|
return self.initialize_subcommand(subc, subargv)
|
|
|
|
|
|
# Arguments after a '--' argument are for the script IPython may be
|
|
|
# about to run, not IPython iteslf. For arguments parsed here (help and
|
|
|
# version), we want to only search the arguments up to the first
|
|
|
# occurrence of '--', which we're calling interpreted_argv.
|
|
|
try:
|
|
|
interpreted_argv = argv[:argv.index('--')]
|
|
|
except ValueError:
|
|
|
interpreted_argv = argv
|
|
|
|
|
|
if any(x in interpreted_argv for x in ('-h', '--help-all', '--help')):
|
|
|
self.print_help('--help-all' in interpreted_argv)
|
|
|
self.exit(0)
|
|
|
|
|
|
if '--version' in interpreted_argv or '-V' in interpreted_argv:
|
|
|
self.print_version()
|
|
|
self.exit(0)
|
|
|
|
|
|
# flatten flags&aliases, so cl-args get appropriate priority:
|
|
|
flags,aliases = self.flatten_flags()
|
|
|
loader = KVArgParseConfigLoader(argv=argv, aliases=aliases,
|
|
|
flags=flags, log=self.log)
|
|
|
config = loader.load_config()
|
|
|
self.update_config(config)
|
|
|
# store unparsed args in extra_args
|
|
|
self.extra_args = loader.extra_args
|
|
|
|
|
|
@classmethod
|
|
|
def _load_config_files(cls, basefilename, path=None, log=None):
|
|
|
"""Load config files (py,json) by filename and path.
|
|
|
|
|
|
yield each config object in turn.
|
|
|
"""
|
|
|
|
|
|
if not isinstance(path, list):
|
|
|
path = [path]
|
|
|
for path in path[::-1]:
|
|
|
# path list is in descending priority order, so load files backwards:
|
|
|
pyloader = PyFileConfigLoader(basefilename+'.py', path=path, log=log)
|
|
|
jsonloader = JSONFileConfigLoader(basefilename+'.json', path=path, log=log)
|
|
|
config = None
|
|
|
for loader in [pyloader, jsonloader]:
|
|
|
try:
|
|
|
config = loader.load_config()
|
|
|
except ConfigFileNotFound:
|
|
|
pass
|
|
|
except Exception:
|
|
|
# try to get the full filename, but it will be empty in the
|
|
|
# unlikely event that the error raised before filefind finished
|
|
|
filename = loader.full_filename or basefilename
|
|
|
# problem while running the file
|
|
|
if log:
|
|
|
log.error("Exception while loading config file %s",
|
|
|
filename, exc_info=True)
|
|
|
else:
|
|
|
if log:
|
|
|
log.debug("Loaded config file: %s", loader.full_filename)
|
|
|
if config:
|
|
|
yield config
|
|
|
|
|
|
raise StopIteration
|
|
|
|
|
|
|
|
|
@catch_config_error
|
|
|
def load_config_file(self, filename, path=None):
|
|
|
"""Load config files by filename and path."""
|
|
|
filename, ext = os.path.splitext(filename)
|
|
|
loaded = []
|
|
|
for config in self._load_config_files(filename, path=path, log=self.log):
|
|
|
loaded.append(config)
|
|
|
self.update_config(config)
|
|
|
if len(loaded) > 1:
|
|
|
collisions = loaded[0].collisions(loaded[1])
|
|
|
if collisions:
|
|
|
self.log.warn("Collisions detected in {0}.py and {0}.json config files."
|
|
|
" {0}.json has higher priority: {1}".format(
|
|
|
filename, json.dumps(collisions, indent=2),
|
|
|
))
|
|
|
|
|
|
|
|
|
def generate_config_file(self):
|
|
|
"""generate default config file from Configurables"""
|
|
|
lines = ["# Configuration file for %s."%self.name]
|
|
|
lines.append('')
|
|
|
lines.append('c = get_config()')
|
|
|
lines.append('')
|
|
|
for cls in self._config_classes:
|
|
|
lines.append(cls.class_config_section())
|
|
|
return '\n'.join(lines)
|
|
|
|
|
|
def exit(self, exit_status=0):
|
|
|
self.log.debug("Exiting application: %s" % self.name)
|
|
|
sys.exit(exit_status)
|
|
|
|
|
|
@classmethod
|
|
|
def launch_instance(cls, argv=None, **kwargs):
|
|
|
"""Launch a global instance of this Application
|
|
|
|
|
|
If a global instance already exists, this reinitializes and starts it
|
|
|
"""
|
|
|
app = cls.instance(**kwargs)
|
|
|
app.initialize(argv)
|
|
|
app.start()
|
|
|
|
|
|
#-----------------------------------------------------------------------------
|
|
|
# utility functions, for convenience
|
|
|
#-----------------------------------------------------------------------------
|
|
|
|
|
|
def boolean_flag(name, configurable, set_help='', unset_help=''):
|
|
|
"""Helper for building basic --trait, --no-trait flags.
|
|
|
|
|
|
Parameters
|
|
|
----------
|
|
|
|
|
|
name : str
|
|
|
The name of the flag.
|
|
|
configurable : str
|
|
|
The 'Class.trait' string of the trait to be set/unset with the flag
|
|
|
set_help : unicode
|
|
|
help string for --name flag
|
|
|
unset_help : unicode
|
|
|
help string for --no-name flag
|
|
|
|
|
|
Returns
|
|
|
-------
|
|
|
|
|
|
cfg : dict
|
|
|
A dict with two keys: 'name', and 'no-name', for setting and unsetting
|
|
|
the trait, respectively.
|
|
|
"""
|
|
|
# default helpstrings
|
|
|
set_help = set_help or "set %s=True"%configurable
|
|
|
unset_help = unset_help or "set %s=False"%configurable
|
|
|
|
|
|
cls,trait = configurable.split('.')
|
|
|
|
|
|
setter = {cls : {trait : True}}
|
|
|
unsetter = {cls : {trait : False}}
|
|
|
return {name : (setter, set_help), 'no-'+name : (unsetter, unset_help)}
|
|
|
|
|
|
|
|
|
def get_config():
|
|
|
"""Get the config object for the global Application instance, if there is one
|
|
|
|
|
|
otherwise return an empty config object
|
|
|
"""
|
|
|
if Application.initialized():
|
|
|
return Application.instance().config
|
|
|
else:
|
|
|
return Config()
|
|
|
|
