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fix access to png width and height in nbconvert html basic template
fix access to png width and height in nbconvert html basic template

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application.py
621 lines | 22.2 KiB | text/x-python | PythonLexer
# encoding: utf-8
"""A base class for a configurable application."""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
from __future__ import print_function
import json
import logging
import os
import re
import sys
from copy import deepcopy
from collections import defaultdict
from IPython.external.decorator import decorator
from IPython.config.configurable import SingletonConfigurable
from IPython.config.loader import (
KVArgParseConfigLoader, PyFileConfigLoader, Config, ArgumentError, ConfigFileNotFound, JSONFileConfigLoader
)
from IPython.utils.traitlets import (
Unicode, List, Enum, Dict, Instance, TraitError
)
from IPython.utils.importstring import import_item
from IPython.utils.text import indent, wrap_paragraphs, dedent
from IPython.utils import py3compat
from IPython.utils.py3compat import string_types, iteritems
#-----------------------------------------------------------------------------
# Descriptions for the various sections
#-----------------------------------------------------------------------------
# merge flags&aliases into options
option_description = """
Arguments that take values are actually convenience aliases to full
Configurables, whose aliases are listed on the help line. For more information
on full configurables, see '--help-all'.
""".strip() # trim newlines of front and back
keyvalue_description = """
Parameters are set from command-line arguments of the form:
`--Class.trait=value`.
This line is evaluated in Python, so simple expressions are allowed, e.g.::
`--C.a='range(3)'` For setting C.a=[0,1,2].
""".strip() # trim newlines of front and back
# sys.argv can be missing, for example when python is embedded. See the docs
# for details: http://docs.python.org/2/c-api/intro.html#embedding-python
if not hasattr(sys, "argv"):
sys.argv = [""]
subcommand_description = """
Subcommands are launched as `{app} cmd [args]`. For information on using
subcommand 'cmd', do: `{app} cmd -h`.
"""
# get running program name
#-----------------------------------------------------------------------------
# Application class
#-----------------------------------------------------------------------------
@decorator
def catch_config_error(method, app, *args, **kwargs):
"""Method decorator for catching invalid config (Trait/ArgumentErrors) during init.
On a TraitError (generally caused by bad config), this will print the trait's
message, and exit the app.
For use on init methods, to prevent invoking excepthook on invalid input.
"""
try:
return method(app, *args, **kwargs)
except (TraitError, ArgumentError) as e:
app.print_help()
app.log.fatal("Bad config encountered during initialization:")
app.log.fatal(str(e))
app.log.debug("Config at the time: %s", app.config)
app.exit(1)
class ApplicationError(Exception):
pass
class LevelFormatter(logging.Formatter):
"""Formatter with additional `highlevel` record
This field is empty if log level is less than highlevel_limit,
otherwise it is formatted with self.highlevel_format.
Useful for adding 'WARNING' to warning messages,
without adding 'INFO' to info, etc.
"""
highlevel_limit = logging.WARN
highlevel_format = " %(levelname)s |"
def format(self, record):
if record.levelno >= self.highlevel_limit:
record.highlevel = self.highlevel_format % record.__dict__
else:
record.highlevel = ""
return super(LevelFormatter, self).format(record)
class Application(SingletonConfigurable):
"""A singleton application with full configuration support."""
# The name of the application, will usually match the name of the command
# line application
name = Unicode(u'application')
# The description of the application that is printed at the beginning
# of the help.
description = Unicode(u'This is an application.')
# default section descriptions
option_description = Unicode(option_description)
keyvalue_description = Unicode(keyvalue_description)
subcommand_description = Unicode(subcommand_description)
# The usage and example string that goes at the end of the help string.
examples = Unicode()
# A sequence of Configurable subclasses whose config=True attributes will
# be exposed at the command line.
classes = []
@property
def _help_classes(self):
"""Define `App.help_classes` if CLI classes should differ from config file classes"""
return getattr(self, 'help_classes', self.classes)
@property
def _config_classes(self):
"""Define `App.config_classes` if config file classes should differ from CLI classes."""
return getattr(self, 'config_classes', self.classes)
# The version string of this application.
version = Unicode(u'0.0')
# the argv used to initialize the application
argv = List()
# The log level for the application
log_level = Enum((0,10,20,30,40,50,'DEBUG','INFO','WARN','ERROR','CRITICAL'),
default_value=logging.WARN,
config=True,
help="Set the log level by value or name.")
def _log_level_changed(self, name, old, new):
"""Adjust the log level when log_level is set."""
if isinstance(new, string_types):
new = getattr(logging, new)
self.log_level = new
self.log.setLevel(new)
_log_formatter_cls = LevelFormatter
log_datefmt = Unicode("%Y-%m-%d %H:%M:%S", config=True,
help="The date format used by logging formatters for %(asctime)s"
)
def _log_datefmt_changed(self, name, old, new):
self._log_format_changed()
log_format = Unicode("[%(name)s]%(highlevel)s %(message)s", config=True,
help="The Logging format template",
)
def _log_format_changed(self, name, old, new):
"""Change the log formatter when log_format is set."""
_log_handler = self.log.handlers[0]
_log_formatter = self._log_formatter_cls(fmt=new, datefmt=self.log_datefmt)
_log_handler.setFormatter(_log_formatter)
log = Instance(logging.Logger)
def _log_default(self):
"""Start logging for this application.
The default is to log to stderr using a StreamHandler, if no default
handler already exists. The log level starts at logging.WARN, but this
can be adjusted by setting the ``log_level`` attribute.
"""
log = logging.getLogger(self.__class__.__name__)
log.setLevel(self.log_level)
log.propagate = False
_log = log # copied from Logger.hasHandlers() (new in Python 3.2)
while _log:
if _log.handlers:
return log
if not _log.propagate:
break
else:
_log = _log.parent
if sys.executable.endswith('pythonw.exe'):
# this should really go to a file, but file-logging is only
# hooked up in parallel applications
_log_handler = logging.StreamHandler(open(os.devnull, 'w'))
else:
_log_handler = logging.StreamHandler()
_log_formatter = self._log_formatter_cls(fmt=self.log_format, datefmt=self.log_datefmt)
_log_handler.setFormatter(_log_formatter)
log.addHandler(_log_handler)
return log
# the alias map for configurables
aliases = Dict({'log-level' : 'Application.log_level'})
# flags for loading Configurables or store_const style flags
# flags are loaded from this dict by '--key' flags
# this must be a dict of two-tuples, the first element being the Config/dict
# and the second being the help string for the flag
flags = Dict()
def _flags_changed(self, name, old, new):
"""ensure flags dict is valid"""
for key,value in iteritems(new):
assert len(value) == 2, "Bad flag: %r:%s"%(key,value)
assert isinstance(value[0], (dict, Config)), "Bad flag: %r:%s"%(key,value)
assert isinstance(value[1], string_types), "Bad flag: %r:%s"%(key,value)
# subcommands for launching other applications
# if this is not empty, this will be a parent Application
# this must be a dict of two-tuples,
# the first element being the application class/import string
# and the second being the help string for the subcommand
subcommands = Dict()
# parse_command_line will initialize a subapp, if requested
subapp = Instance('IPython.config.application.Application', allow_none=True)
# extra command-line arguments that don't set config values
extra_args = List(Unicode)
def __init__(self, **kwargs):
SingletonConfigurable.__init__(self, **kwargs)
# Ensure my class is in self.classes, so my attributes appear in command line
# options and config files.
if self.__class__ not in self.classes:
self.classes.insert(0, self.__class__)
def _config_changed(self, name, old, new):
SingletonConfigurable._config_changed(self, name, old, new)
self.log.debug('Config changed:')
self.log.debug(repr(new))
@catch_config_error
def initialize(self, argv=None):
"""Do the basic steps to configure me.
Override in subclasses.
"""
self.parse_command_line(argv)
def start(self):
"""Start the app mainloop.
Override in subclasses.
"""
if self.subapp is not None:
return self.subapp.start()
def print_alias_help(self):
"""Print the alias part of the help."""
if not self.aliases:
return
lines = []
classdict = {}
for cls in self._help_classes:
# include all parents (up to, but excluding Configurable) in available names
for c in cls.mro()[:-3]:
classdict[c.__name__] = c
for alias, longname in iteritems(self.aliases):
classname, traitname = longname.split('.',1)
cls = classdict[classname]
trait = cls.class_traits(config=True)[traitname]
help = cls.class_get_trait_help(trait).splitlines()
# reformat first line
help[0] = help[0].replace(longname, alias) + ' (%s)'%longname
if len(alias) == 1:
help[0] = help[0].replace('--%s='%alias, '-%s '%alias)
lines.extend(help)
# lines.append('')
print(os.linesep.join(lines))
def print_flag_help(self):
"""Print the flag part of the help."""
if not self.flags:
return
lines = []
for m, (cfg,help) in iteritems(self.flags):
prefix = '--' if len(m) > 1 else '-'
lines.append(prefix+m)
lines.append(indent(dedent(help.strip())))
# lines.append('')
print(os.linesep.join(lines))
def print_options(self):
if not self.flags and not self.aliases:
return
lines = ['Options']
lines.append('-'*len(lines[0]))
lines.append('')
for p in wrap_paragraphs(self.option_description):
lines.append(p)
lines.append('')
print(os.linesep.join(lines))
self.print_flag_help()
self.print_alias_help()
print()
def print_subcommands(self):
"""Print the subcommand part of the help."""
if not self.subcommands:
return
lines = ["Subcommands"]
lines.append('-'*len(lines[0]))
lines.append('')
for p in wrap_paragraphs(self.subcommand_description.format(
app=self.name)):
lines.append(p)
lines.append('')
for subc, (cls, help) in iteritems(self.subcommands):
lines.append(subc)
if help:
lines.append(indent(dedent(help.strip())))
lines.append('')
print(os.linesep.join(lines))
def print_help(self, classes=False):
"""Print the help for each Configurable class in self.classes.
If classes=False (the default), only flags and aliases are printed.
"""
self.print_description()
self.print_subcommands()
self.print_options()
if classes:
help_classes = self._help_classes
if help_classes:
print("Class parameters")
print("----------------")
print()
for p in wrap_paragraphs(self.keyvalue_description):
print(p)
print()
for cls in help_classes:
cls.class_print_help()
print()
else:
print("To see all available configurables, use `--help-all`")
print()
self.print_examples()
def print_description(self):
"""Print the application description."""
for p in wrap_paragraphs(self.description):
print(p)
print()
def print_examples(self):
"""Print usage and examples.
This usage string goes at the end of the command line help string
and should contain examples of the application's usage.
"""
if self.examples:
print("Examples")
print("--------")
print()
print(indent(dedent(self.examples.strip())))
print()
def print_version(self):
"""Print the version string."""
print(self.version)
def update_config(self, config):
"""Fire the traits events when the config is updated."""
# Save a copy of the current config.
newconfig = deepcopy(self.config)
# Merge the new config into the current one.
newconfig.merge(config)
# Save the combined config as self.config, which triggers the traits
# events.
self.config = newconfig
@catch_config_error
def initialize_subcommand(self, subc, argv=None):
"""Initialize a subcommand with argv."""
subapp,help = self.subcommands.get(subc)
if isinstance(subapp, string_types):
subapp = import_item(subapp)
# clear existing instances
self.__class__.clear_instance()
# instantiate
self.subapp = subapp.instance(config=self.config)
# and initialize subapp
self.subapp.initialize(argv)
def flatten_flags(self):
"""flatten flags and aliases, so cl-args override as expected.
This prevents issues such as an alias pointing to InteractiveShell,
but a config file setting the same trait in TerminalInteraciveShell
getting inappropriate priority over the command-line arg.
Only aliases with exactly one descendent in the class list
will be promoted.
"""
# build a tree of classes in our list that inherit from a particular
# it will be a dict by parent classname of classes in our list
# that are descendents
mro_tree = defaultdict(list)
for cls in self._help_classes:
clsname = cls.__name__
for parent in cls.mro()[1:-3]:
# exclude cls itself and Configurable,HasTraits,object
mro_tree[parent.__name__].append(clsname)
# flatten aliases, which have the form:
# { 'alias' : 'Class.trait' }
aliases = {}
for alias, cls_trait in iteritems(self.aliases):
cls,trait = cls_trait.split('.',1)
children = mro_tree[cls]
if len(children) == 1:
# exactly one descendent, promote alias
cls = children[0]
aliases[alias] = '.'.join([cls,trait])
# 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()