def DEFINE_flag(flag, flag_values=FLAGS, module_name=None): # pylint: disable=g-bad-name
"""Registers a 'Flag' object with a 'FlagValues' object.
By default, the global FLAGS 'FlagValue' object is used.
Typical users will use one of the more specialized DEFINE_xxx
functions, such as DEFINE_string or DEFINE_integer. But developers
who need to create Flag objects themselves should use this function
to register their flags.
Args:
flag: A Flag object, a flag that is key to the module.
flag_values: FlagValues object with which the flag will be registered.
module_name: A string, the name of the Python module declaring this flag.
If not provided, it will be computed using the stack trace of this call.
"""
# copying the reference to flag_values prevents pychecker warnings
fv = flag_values
fv[flag.name] = flag
# Tell flag_values who's defining the flag.
if isinstance(flag_values, FlagValues):
# Regarding the above isinstance test: some users pass funny
# values of flag_values (e.g., {}) in order to avoid the flag
# registration (in the past, there used to be a flag_values ==
# FLAGS test here) and redefine flags with the same name (e.g.,
# debug). To avoid breaking their code, we perform the
# registration only if flag_values is a real FlagValues object.
if module_name:
module = sys.modules.get(module_name)
else:
module, module_name = _helpers.GetCallingModuleObjectAndName()
# TODO(vrusinov): _RegisterFlagByModule* should be public.
# pylint: disable=protected-access
flag_values._RegisterFlagByModule(module_name, flag)
flag_values._RegisterFlagByModuleId(id(module), flag)
def __setitem__(self, name, flag):
"""Registers a new flag variable."""
fl = self.FlagDict()
if not isinstance(flag, _flag.Flag):
raise exceptions.IllegalFlagValue(flag)
if str is bytes and isinstance(name, unicode):
# When using Python 2 with unicode_literals, allow it but encode it
# into the bytes type we require.
name = name.encode('utf-8')
if not isinstance(name, type('')):
raise exceptions.FlagsError('Flag name must be a string')
if not name:
raise exceptions.FlagsError('Flag name cannot be empty')
if name in fl and not flag.allow_override and not fl[
name].allow_override:
module, module_name = _helpers.GetCallingModuleObjectAndName()
if (self.FindModuleDefiningFlag(name) == module_name
and id(module) != self.FindModuleIdDefiningFlag(name)):
# If the flag has already been defined by a module with the same name,
# but a different ID, we can stop here because it indicates that the
# module is simply being imported a subsequent time.
return
raise exceptions.DuplicateFlagError(name, self)
short_name = flag.short_name
if short_name is not None:
if (short_name in fl and not flag.allow_override
and not fl[short_name].allow_override):
raise exceptions.DuplicateFlagError(short_name, self)
fl[short_name] = flag
if (name not in fl # new flag
or fl[name].using_default_value
or not flag.using_default_value):
fl[name] = flag
