"""optik.option
Defines the Option class and some standard value-checking functions.
Cheetah modifications: added "Cheetah.Utils.optik." prefix to
all intra-Optik imports.
"""
__revision__ = "$Id: option.py,v 1.2 2002/09/12 06:56:51 hierro Exp $"
# Copyright (c) 2001 Gregory P. Ward. All rights reserved.
# See the README.txt distributed with Optik for licensing terms.
# created 2001/10/17, GPW (from optik.py)
import sys
from types import TupleType, DictType
from Cheetah.Utils.optik.errors import OptionError, OptionValueError
_builtin_cvt = { "int" : (int, "integer"),
"long" : (long, "long integer"),
"float" : (float, "floating-point"),
"complex" : (complex, "complex") }
def check_builtin (option, opt, value):
(cvt, what) = _builtin_cvt[option.type]
try:
return cvt(value)
except ValueError:
raise OptionValueError(
#"%s: invalid %s argument %r" % (opt, what, value))
"option %s: invalid %s value: %r" % (opt, what, value))
# Not supplying a default is different from a default of None,
# so we need an explicit "not supplied" value.
NO_DEFAULT = "NO"+"DEFAULT"
class Option:
"""
Instance attributes:
_short_opts : [string]
_long_opts : [string]
action : string
type : string
dest : string
default : any
nargs : int
const : any
callback : function
callback_args : (any*)
callback_kwargs : { string : any }
help : string
metavar : string
"""
# The list of instance attributes that may be set through
# keyword args to the constructor.
ATTRS = ['action',
'type',
'dest',
'default',
'nargs',
'const',
'callback',
'callback_args',
'callback_kwargs',
'help',
'metavar']
# The set of actions allowed by option parsers. Explicitly listed
# here so the constructor can validate its arguments.
ACTIONS = ("store",
"store_const",
"store_true",
"store_false",
"append",
"count",
"callback",
"help",
"version")
# The set of actions that involve storing a value somewhere;
# also listed just for constructor argument validation. (If
# the action is one of these, there must be a destination.)
STORE_ACTIONS = ("store",
"store_const",
"store_true",
"store_false",
"append",
"count")
# The set of actions for which it makes sense to supply a value
# type, ie. where we expect an argument to this option.
TYPED_ACTIONS = ("store",
"append",
"callback")
# The set of known types for option parsers. Again, listed here for
# constructor argument validation.
TYPES = ("string", "int", "long", "float", "complex")
# Dictionary of argument checking functions, which convert and
# validate option arguments according to the option type.
#
# Signature of checking functions is:
# check(option : Option, opt : string, value : string) -> any
# where
# option is the Option instance calling the checker
# opt is the actual option seen on the command-line
# (eg. "-a", "--file")
# value is the option argument seen on the command-line
#
# The return value should be in the appropriate Python type
# for option.type -- eg. an integer if option.type == "int".
#
# If no checker is defined for a type, arguments will be
# unchecked and remain strings.
TYPE_CHECKER = { "int" : check_builtin,
"long" : check_builtin,
"float" : check_builtin,
"complex" : check_builtin,
}
# CHECK_METHODS is a list of unbound method objects; they are called
# by the constructor, in order, after all attributes are
# initialized. The list is created and filled in later, after all
# the methods are actually defined. (I just put it here because I
# like to define and document all class attributes in the same
# place.) Subclasses that add another _check_*() method should
# define their own CHECK_METHODS list that adds their check method
# to those from this class.
CHECK_METHODS = None
# -- Constructor/initialization methods ----------------------------
def __init__ (self, *opts, **attrs):
# Set _short_opts, _long_opts attrs from 'opts' tuple
opts = self._check_opt_strings(opts)
self._set_opt_strings(opts)
# Set all other attrs (action, type, etc.) from 'attrs' dict
self._set_attrs(attrs)
# Check all the attributes we just set. There are lots of
# complicated interdependencies, but luckily they can be farmed
# out to the _check_*() methods listed in CHECK_METHODS -- which
# could be handy for subclasses! The one thing these all share
# is that they raise OptionError if they discover a problem.
for checker in self.CHECK_METHODS:
checker(self)
def _check_opt_strings (self, opts):
# Filter out None because early versions of Optik had exactly
# one short option and one long option, either of which
# could be None.
opts = filter(None, opts)
if not opts:
raise OptionError("at least one option string must be supplied",
self)
return opts
def _set_opt_strings (self, opts):
self._short_opts = []
self._long_opts = []
for opt in opts:
if len(opt) < 2:
raise OptionError(
"invalid option string %r: "
"must be at least two characters long" % opt, self)
elif len(opt) == 2:
if not (opt[0] == "-" and opt[1] != "-"):
raise OptionError(
"invalid short option string %r: "
"must be of the form -x, (x any non-dash char)" % opt,
self)
self._short_opts.append(opt)
else:
if not (opt[0:2] == "--" and opt[2] != "-"):
raise OptionError(
"invalid long option string %r: "
"must start with --, followed by non-dash" % opt,
self)
self._long_opts.append(opt)
def _set_attrs (self, attrs):
for attr in self.ATTRS:
if attrs.has_key(attr):
setattr(self, attr, attrs[attr])
del attrs[attr]
else:
if attr == 'default':
setattr(self, attr, NO_DEFAULT)
else:
setattr(self, attr, None)
if attrs:
raise OptionError(
"invalid keyword arguments: %s" % ", ".join(attrs.keys()),
self)
# -- Constructor validation methods --------------------------------
def _check_action (self):
if self.action is None:
self.action = "store"
elif self.action not in self.ACTIONS:
raise OptionError("invalid action: %r" % self.action, self)
def _check_type (self):
if self.type is None:
# XXX should factor out another class attr here: list of
# actions that *require* a type
if self.action in ("store", "append"):
# No type given? "string" is the most sensible default.
self.type = "string"
else:
if self.type not in self.TYPES:
raise OptionError("invalid option type: %r" % self.type, self)
if self.action not in self.TYPED_ACTIONS:
raise OptionError(
"must not supply a type for action %r" % self.action, self)
def _check_dest (self):
if self.action in self.STORE_ACTIONS and self.dest is None:
# No destination given, and we need one for this action.
# Glean a destination from the first long option string,
# or from the first short option string if no long options.
if self._long_opts:
# eg. "--foo-bar" -> "foo_bar"
self.dest = self._long_opts[0][2:].replace('-', '_')
else:
self.dest = self._short_opts[0][1]
def _check_const (self):
if self.action != "store_const" and self.const is not None:
raise OptionError(
"'const' must not be supplied for action %r" % self.action,
self)
def _check_nargs (self):
if self.action in self.TYPED_ACTIONS:
if self.nargs is None:
self.nargs = 1
elif self.nargs is not None:
raise OptionError(
"'nargs' must not be supplied for action %r" % self.action,
self)
def _check_callback (self):
if self.action == "callback":
if not callable(self.callback):
raise OptionError(
"callback not callable: %r" % self.callback, self)
if (self.callback_args is not None and
type(self.callback_args) is not TupleType):
raise OptionError(
"callback_args, if supplied, must be a tuple: not %r"
% self.callback_args, self)
if (self.callback_kwargs is not None and
type(self.callback_kwargs) is not DictType):
raise OptionError(
"callback_kwargs, if supplied, must be a dict: not %r"
% self.callback_kwargs, self)
else:
if self.callback is not None:
raise OptionError(
"callback supplied (%r) for non-callback option"
% self.callback, self)
if self.callback_args is not None:
raise OptionError(
"callback_args supplied for non-callback option", self)
if self.callback_kwargs is not None:
raise OptionError(
"callback_kwargs supplied for non-callback option", self)
CHECK_METHODS = [_check_action,
_check_type,
_check_dest,
_check_const,
_check_nargs,
_check_callback]
# -- Miscellaneous methods -----------------------------------------
def __str__ (self):
if self._short_opts or self._long_opts:
return "/".join(self._short_opts + self._long_opts)
else:
raise RuntimeError, "short_opts and long_opts both empty!"
def takes_value (self):
return self.type is not None
# -- Processing methods --------------------------------------------
def check_value (self, opt, value):
checker = self.TYPE_CHECKER.get(self.type)
if checker is None:
return value
else:
return checker(self, opt, value)
def process (self, opt, value, values, parser):
# First, convert the value(s) to the right type. Howl if any
# value(s) are bogus.
if value is not None:
if self.nargs == 1:
value = self.check_value(opt, value)
else:
value = tuple([self.check_value(opt, v) for v in value])
# And then take whatever action is expected of us.
# This is a separate method to make life easier for
# subclasses to add new actions.
return self.take_action(
self.action, self.dest, opt, value, values, parser)
def take_action (self, action, dest, opt, value, values, parser):
if action == "store":
setattr(values, dest, value)
elif action == "store_const":
setattr(values, dest, self.const)
elif action == "store_true":
setattr(values, dest, 1)
elif action == "store_false":
setattr(values, dest, 0)
elif action == "append":
values.ensure_value(dest, []).append(value)
elif action == "count":
setattr(values, dest, values.ensure_value(dest, 0) + 1)
elif action == "callback":
args = self.callback_args or ()
kwargs = self.callback_kwargs or {}
self.callback(self, opt, value, parser, *args, **kwargs)
elif action == "help":
parser.print_help()
sys.exit(0)
elif action == "version":
parser.print_version()
sys.exit(0)
else:
raise RuntimeError, "unknown action %r" % self.action
return 1
# class Option
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