Python ranked_value.RankedValue類代碼示例

 def _format_record(self, record):
   value_color = green if self.get_options().colors else lambda x: x
   rank_color = self._rank_color(record.rank)
   return '{value} {rank}'.format(
     value=value_color(str(record.value)),
     rank=rank_color('(from {rank}{details})'.format(
       rank=RankedValue.get_rank_name(record.rank),
       details=' {}'.format(record.details) if record.details else '',
     )),
   )

 def register_options(cls, register):
   super(ExplainOptionsTask, cls).register_options(register)
   register('--scope', help='Only show options in this scope.')
   register('--name', help='Only show options with this name.')
   register('--rank', choices=RankedValue.get_names(),
            help='Only show options with at least this importance.')
   register('--show-history', action='store_true', default=False,
            help='Show the previous values options had before being overridden.')
   register('--only-overridden', action='store_true', default=False,
            help='Only show values that overrode defaults.')

 def register_options(cls, register):
   super(ExplainOptionsTask, cls).register_options(register)
   register('--scope', help='Only show options in this scope.')
   register('--name', help='Only show options with this name.')
   register('--rank', choices=RankedValue.get_names(),
            help='Only show options with at least this importance.')
   register('--show-history', type=bool,
            help='Show the previous values options had before being overridden.')
   register('--only-overridden', type=bool,
            help='Only show values that overrode defaults.')
   register('--skip-inherited', type=bool, default=True,
            help='Do not show inherited options, unless their values differ from their parents.')

  def _compute_default(self, dest, kwargs):
    """Compute the default value to use for an option's registration.

    The source of the default value is chosen according to the ranking in RankedValue.
    """
    config_section = 'DEFAULT' if self._scope == GLOBAL_SCOPE else self._scope
    env_var = 'PANTS_{0}_{1}'.format(config_section.upper().replace('.', '_'), dest.upper())
    value_type = kwargs.get('type', str)
    env_val_str = self._env.get(env_var) if self._env else None

    env_val = None if env_val_str is None else value_type(env_val_str)
    config_val = self._config.get(config_section, dest, default=None) if self._config else None
    hardcoded_val = kwargs.get('default')
    return RankedValue.choose(None, env_val, config_val, hardcoded_val)

 def _format_record(self, record):
   simple_rank = RankedValue.get_rank_name(record.rank)
   if self.is_json():
     return record.value, simple_rank
   elif self.is_text():
     simple_value = str(record.value)
     value_color = green if self.get_options().colors else lambda x: x
     formatted_value = value_color(simple_value)
     rank_color = self._rank_color(record.rank)
     formatted_rank = '(from {rank}{details})'.format(
       rank=simple_rank,
       details=rank_color(' {}'.format(record.details)) if record.details else '',
     )
     return '{value} {rank}'.format(
       value=formatted_value,
       rank=formatted_rank,
     )

  def _compute_default(self, dest, kwargs):
    """Compute the default value to use for an option's registration.

    The source of the default value is chosen according to the ranking in RankedValue.
    """
    config_section = 'DEFAULT' if self._scope == GLOBAL_SCOPE else self._scope
    udest = dest.upper()
    if self._scope == GLOBAL_SCOPE:
      # For convenience, we allow three forms of env var for global scope options.
      # The fully-specified env var is PANTS_DEFAULT_FOO, which is uniform with PANTS_<SCOPE>_FOO
      # for all the other scopes.  However we also allow simply PANTS_FOO. And if the option name
      # itself starts with 'pants-' then we also allow simply FOO. E.g., PANTS_WORKDIR instead of
      # PANTS_PANTS_WORKDIR or PANTS_DEFAULT_PANTS_WORKDIR. We take the first specified value we
      # find, in this order: PANTS_DEFAULT_FOO, PANTS_FOO, FOO.
      env_vars = ['PANTS_DEFAULT_{0}'.format(udest), 'PANTS_{0}'.format(udest)]
      if udest.startswith('PANTS_'):
        env_vars.append(udest)
    else:
      sanitized_env_var_scope = self._ENV_SANITIZER_RE.sub('_', config_section.upper())
      env_vars = ['PANTS_{0}_{1}'.format(sanitized_env_var_scope, udest)]
    value_type = self.str_to_bool if is_boolean_flag(kwargs) else kwargs.get('type', str)
    env_val_str = None
    if self._env:
      for env_var in env_vars:
        if env_var in self._env:
          env_val_str = self._env.get(env_var)
          break
    env_val = None if env_val_str is None else value_type(env_val_str)
    if kwargs.get('action') == 'append':
      config_val_strs = self._config.getlist(config_section, dest) if self._config else None
      config_val = (None if config_val_strs is None else
                    [value_type(config_val_str) for config_val_str in config_val_strs])
      default = []
    else:
      config_val_str = (self._config.get(config_section, dest, default=None)
                        if self._config else None)
      config_val = None if config_val_str is None else value_type(config_val_str)
      default = None
    hardcoded_val = kwargs.get('default')
    return RankedValue.choose(None, env_val, config_val, hardcoded_val, default)

 def _rank_filter(self, rank):
   pattern = self.get_options().rank
   if not pattern:
     return True
   return rank >= RankedValue.get_rank_value(pattern)

  def _compute_value(self, dest, kwargs, flag_vals):
    """Compute the value to use for an option.

    The source of the default value is chosen according to the ranking in RankedValue.
    """
    is_fromfile = kwargs.get('fromfile', False)
    action = kwargs.get('action')
    if is_fromfile and action and action != 'append':
      raise ParseError('Cannot fromfile {} with an action ({}) in scope {}'
                       .format(dest, action, self._scope))

    config_section = GLOBAL_SCOPE_CONFIG_SECTION if self._scope == GLOBAL_SCOPE else self._scope
    udest = dest.upper()
    if self._scope == GLOBAL_SCOPE:
      # For convenience, we allow three forms of env var for global scope options.
      # The fully-specified env var is PANTS_DEFAULT_FOO, which is uniform with PANTS_<SCOPE>_FOO
      # for all the other scopes.  However we also allow simply PANTS_FOO. And if the option name
      # itself starts with 'pants-' then we also allow simply FOO. E.g., PANTS_WORKDIR instead of
      # PANTS_PANTS_WORKDIR or PANTS_DEFAULT_PANTS_WORKDIR. We take the first specified value we
      # find, in this order: PANTS_DEFAULT_FOO, PANTS_FOO, FOO.
      env_vars = ['PANTS_DEFAULT_{0}'.format(udest), 'PANTS_{0}'.format(udest)]
      if udest.startswith('PANTS_'):
        env_vars.append(udest)
    else:
      sanitized_env_var_scope = self._ENV_SANITIZER_RE.sub('_', config_section.upper())
      env_vars = ['PANTS_{0}_{1}'.format(sanitized_env_var_scope, udest)]

    value_type = self.str_to_bool if is_boolean_flag(kwargs) else kwargs.get('type', str)

    env_val_str = None
    if self._env:
      for env_var in env_vars:
        if env_var in self._env:
          env_val_str = self._env.get(env_var)
          break

    config_val_str = self._config.get(config_section, dest, default=None)
    config_source_file = self._config.get_source_for_option(config_section, dest)
    if config_source_file is not None:
      config_source_file = os.path.relpath(config_source_file)

    def expand(val_str):
      if is_fromfile and val_str and val_str.startswith('@') and not val_str.startswith('@@'):
        fromfile = val_str[1:]
        try:
          with open(fromfile) as fp:
            return fp.read().strip()
        except IOError as e:
          raise self.FromfileError('Failed to read {} in {} from file {}: {}'.format(
            dest, self._scope_str(), fromfile, e))
      else:
        # Support a literal @ for fromfile values via @@.
        return val_str[1:] if is_fromfile and val_str.startswith('@@') else val_str

    def parse_typed_list(val_str):
      return None if val_str is None else [value_type(x) for x in list_option(expand(val_str))]

    def parse_typed_item(val_str):
      return None if val_str is None else value_type(expand(val_str))

    flag_val = None
    if flag_vals:
      if action == 'append':
        flag_val = [parse_typed_item(v) for v in flag_vals]
      elif len(flag_vals) > 1:
        raise ParseError('Multiple cmd line flags specified for option {} in {}'.format(
          dest, self._scope_str()))
      else:
        flag_val = parse_typed_item(flag_vals[0])

    default, parse = ([], parse_typed_list) if action == 'append' else (None, parse_typed_item)

    config_val = parse(config_val_str)
    env_val = parse(env_val_str)
    hardcoded_val = kwargs.get('default')

    config_details = 'in {}'.format(config_source_file) if config_source_file else None

    # Note: ranked_vals is guaranteed to have at least one element, and none of the values
    # of any of its elements will be None.
    ranked_vals = list(reversed(list(RankedValue.prioritized_iter(
      flag_val, env_val, config_val, hardcoded_val, default))))
    choices = kwargs.get('choices')
    for ranked_val in ranked_vals:
      details = config_details if ranked_val.rank == RankedValue.CONFIG else None
      self._option_tracker.record_option(scope=self._scope,
                                         option=dest,
                                         value=ranked_val.value,
                                         rank=ranked_val.rank,
                                         deprecation_version=kwargs.get('deprecated_version'),
                                         details=details)

    def check(val):
      if choices is not None and val is not None and val not in choices:
        raise ParseError('{} is not an allowed value for option {} in {}. '
                         'Must be one of: {}'.format(
          val, dest, self._scope_str(), choices
        ))
      return val

#.........這裏部分代碼省略.........

  def _compute_value(self, dest, kwargs, flag_val_strs):
    """Compute the value to use for an option.

    The source of the default value is chosen according to the ranking in RankedValue.
    """
    # Helper function to convert a string to a value of the option's type.
    def to_value_type(val_str):
      if val_str is None:
        return None
      elif kwargs.get('type') == bool:
        return self._ensure_bool(val_str)
      else:
        return self._wrap_type(kwargs.get('type', str))(val_str)

    # Helper function to expand a fromfile=True value string, if needed.
    def expand(val_str):
      if kwargs.get('fromfile', False) and val_str and val_str.startswith('@'):
        if val_str.startswith('@@'):   # Support a literal @ for fromfile values via @@.
          return val_str[1:]
        else:
          fromfile = val_str[1:]
          try:
            with open(fromfile) as fp:
              return fp.read().strip()
          except IOError as e:
            raise self.FromfileError('Failed to read {} in {} from file {}: {}'.format(
                dest, self._scope_str(), fromfile, e))
      else:
        return val_str

    # Get value from config files, and capture details about its derivation.
    config_details = None
    config_section = GLOBAL_SCOPE_CONFIG_SECTION if self._scope == GLOBAL_SCOPE else self._scope
    config_val_str = expand(self._config.get(config_section, dest, default=None))
    config_source_file = self._config.get_source_for_option(config_section, dest)
    if config_source_file is not None:
      config_source_file = os.path.relpath(config_source_file)
      config_details = 'in {}'.format(config_source_file)

    # Get value from environment, and capture details about its derivation.
    udest = dest.upper()
    if self._scope == GLOBAL_SCOPE:
      # For convenience, we allow three forms of env var for global scope options.
      # The fully-specified env var is PANTS_GLOBAL_FOO, which is uniform with PANTS_<SCOPE>_FOO
      # for all the other scopes.  However we also allow simply PANTS_FOO. And if the option name
      # itself starts with 'pants-' then we also allow simply FOO. E.g., PANTS_WORKDIR instead of
      # PANTS_PANTS_WORKDIR or PANTS_GLOBAL_PANTS_WORKDIR. We take the first specified value we
      # find, in this order: PANTS_GLOBAL_FOO, PANTS_FOO, FOO.
      env_vars = ['PANTS_GLOBAL_{0}'.format(udest), 'PANTS_{0}'.format(udest)]
      if udest.startswith('PANTS_'):
        env_vars.append(udest)
    else:
      sanitized_env_var_scope = self._ENV_SANITIZER_RE.sub('_', self._scope.upper())
      env_vars = ['PANTS_{0}_{1}'.format(sanitized_env_var_scope, udest)]

    env_val_str = None
    env_details = None
    if self._env:
      for env_var in env_vars:
        if env_var in self._env:
          env_val_str = expand(self._env.get(env_var))
          env_details = 'from env var {}'.format(env_var)
          break

    # Get value from cmd-line flags.
    flag_vals = [to_value_type(expand(x)) for x in flag_val_strs]
    if is_list_option(kwargs):
      # Note: It's important to set flag_val to None if no flags were specified, so we can
      # distinguish between no flags set vs. explicit setting of the value to [].
      flag_val = ListValueComponent.merge(flag_vals) if flag_vals else None
    elif len(flag_vals) > 1:
      raise ParseError('Multiple cmd line flags specified for option {} in {}'.format(
          dest, self._scope_str()))
    elif len(flag_vals) == 1:
      flag_val = flag_vals[0]
    else:
      flag_val = None

    # Rank all available values.
    # Note that some of these values may already be of the value type, but type conversion
    # is idempotent, so this is OK.

    values_to_rank = [to_value_type(x) for x in
                      [flag_val, env_val_str, config_val_str, kwargs.get('default'), None]]
    # Note that ranked_vals will always have at least one element, and all elements will be
    # instances of RankedValue (so none will be None, although they may wrap a None value).
    ranked_vals = list(reversed(list(RankedValue.prioritized_iter(*values_to_rank))))

    # Record info about the derivation of each of the values.
    for ranked_val in ranked_vals:
      if ranked_val.rank == RankedValue.CONFIG:
        details = config_details
      elif ranked_val.rank == RankedValue.ENVIRONMENT:
        details = env_details
      else:
        details = None
      self._option_tracker.record_option(scope=self._scope,
                                         option=dest,
                                         value=ranked_val.value,
                                         rank=ranked_val.rank,
#.........這裏部分代碼省略.........

  def _compute_default(self, kwargs):
    """Compute the default value to use for an option's registration.

    The source of the default value is chosen according to the ranking in RankedValue.

    Note: Only call if kwargs has a 'dest' key set.
    """
    dest = kwargs['dest']
    is_fromfile = kwargs.get('fromfile', False)
    action = kwargs.get('action')
    if is_fromfile and action and action != 'append':
      raise ParseError('Cannot fromfile {} with an action ({}) in scope {}'
                       .format(dest, action, self._scope))

    config_section = 'DEFAULT' if self._scope == GLOBAL_SCOPE else self._scope
    udest = dest.upper()
    if self._scope == GLOBAL_SCOPE:
      # For convenience, we allow three forms of env var for global scope options.
      # The fully-specified env var is PANTS_DEFAULT_FOO, which is uniform with PANTS_<SCOPE>_FOO
      # for all the other scopes.  However we also allow simply PANTS_FOO. And if the option name
      # itself starts with 'pants-' then we also allow simply FOO. E.g., PANTS_WORKDIR instead of
      # PANTS_PANTS_WORKDIR or PANTS_DEFAULT_PANTS_WORKDIR. We take the first specified value we
      # find, in this order: PANTS_DEFAULT_FOO, PANTS_FOO, FOO.
      env_vars = ['PANTS_DEFAULT_{0}'.format(udest), 'PANTS_{0}'.format(udest)]
      if udest.startswith('PANTS_'):
        env_vars.append(udest)
    else:
      sanitized_env_var_scope = self._ENV_SANITIZER_RE.sub('_', config_section.upper())
      env_vars = ['PANTS_{0}_{1}'.format(sanitized_env_var_scope, udest)]

    value_type = self.str_to_bool if is_boolean_flag(kwargs) else kwargs.get('type', str)

    env_val_str = None
    if self._env:
      for env_var in env_vars:
        if env_var in self._env:
          env_val_str = self._env.get(env_var)
          break

    config_val_str = self._config.get(config_section, dest, default=None)
    config_source_file = self._config.get_source_for_option(config_section, dest)
    if config_source_file is not None:
      config_source_file = os.path.relpath(config_source_file)

    def expand(val_str):
      if is_fromfile and val_str and val_str.startswith('@') and not val_str.startswith('@@'):
        fromfile = val_str[1:]
        try:
          with open(fromfile) as fp:
            return fp.read().strip()
        except IOError as e:
          raise self.FromfileError('Failed to read {} from file {}: {}'.format(dest, fromfile, e))
      else:
        # Support a literal @ for fromfile values via @@.
        return val_str[1:] if is_fromfile and val_str.startswith('@@') else val_str

    def parse_typed_list(val_str):
      return None if val_str is None else [value_type(x) for x in list_option(expand(val_str))]

    def parse_typed_item(val_str):
      return None if val_str is None else value_type(expand(val_str))

    # Handle the forthcoming conversions argparse will need to do by placing our parse hook - we
    # handle the conversions for env and config ourselves below.  Unlike the env and config
    # handling, `action='append'` does not need to be handled specially since appended flag values
    # come as single items' thus only `parse_typed_item` is ever needed for the flag value type
    # conversions.
    if is_fromfile:
      kwargs['type'] = parse_typed_item

    default, parse = ([], parse_typed_list) if action == 'append' else (None, parse_typed_item)
    config_val = parse(config_val_str)
    env_val = parse(env_val_str)
    hardcoded_val = kwargs.get('default')

    config_details = 'in {}'.format(config_source_file) if config_source_file else None

    choices = list(RankedValue.prioritized_iter(None, env_val, config_val, hardcoded_val, default))
    for choice in reversed(choices):
      details = config_details if choice.rank == RankedValue.CONFIG else None
      self._option_tracker.record_option(scope=self._scope, option=dest, value=choice.value,
                                         rank=choice.rank, details=details)

    return choices[0]

  def _compute_value(self, dest, kwargs, flag_val_strs):
    """Compute the value to use for an option.

    The source of the default value is chosen according to the ranking in RankedValue.
    """
    # Helper function to convert a string to a value of the option's type.
    def to_value_type(val_str):
      if val_str is None:
        return None
      elif kwargs.get('type') == bool:
        return self._ensure_bool(val_str)
      else:
        type_arg = kwargs.get('type', str)
        try:
          return self._wrap_type(type_arg)(val_str)
        except TypeError as e:
          raise ParseError(
            "Error applying type '{}' to option value '{}', for option '--{}' in {}: {}"
            .format(type_arg.__name__, val_str, dest, self._scope_str(), e))

    # Helper function to expand a fromfile=True value string, if needed.
    # May return a string or a dict/list decoded from a json/yaml file.
    def expand(val_or_str):
      if (kwargs.get('fromfile', True) and val_or_str and
          isinstance(val_or_str, str) and val_or_str.startswith('@')):
        if val_or_str.startswith('@@'):   # Support a literal @ for fromfile values via @@.
          return val_or_str[1:]
        else:
          fromfile = val_or_str[1:]
          try:
            with open(fromfile, 'r') as fp:
              s = fp.read().strip()
              if fromfile.endswith('.json'):
                return json.loads(s)
              elif fromfile.endswith('.yml') or fromfile.endswith('.yaml'):
                return yaml.safe_load(s)
              else:
                return s
          except (IOError, ValueError, yaml.YAMLError) as e:
            raise self.FromfileError('Failed to read {} in {} from file {}: {}'.format(
                dest, self._scope_str(), fromfile, e))
      else:
        return val_or_str

    # Get value from config files, and capture details about its derivation.
    config_details = None
    config_section = GLOBAL_SCOPE_CONFIG_SECTION if self._scope == GLOBAL_SCOPE else self._scope
    config_default_val_or_str = expand(self._config.get(Config.DEFAULT_SECTION, dest, default=None))
    config_val_or_str = expand(self._config.get(config_section, dest, default=None))
    config_source_file = (self._config.get_source_for_option(config_section, dest) or
        self._config.get_source_for_option(Config.DEFAULT_SECTION, dest))
    if config_source_file is not None:
      config_source_file = os.path.relpath(config_source_file)
      config_details = 'in {}'.format(config_source_file)

    # Get value from environment, and capture details about its derivation.
    udest = dest.upper()
    if self._scope == GLOBAL_SCOPE:
      # For convenience, we allow three forms of env var for global scope options.
      # The fully-specified env var is PANTS_GLOBAL_FOO, which is uniform with PANTS_<SCOPE>_FOO
      # for all the other scopes.  However we also allow simply PANTS_FOO. And if the option name
      # itself starts with 'pants-' then we also allow simply FOO. E.g., PANTS_WORKDIR instead of
      # PANTS_PANTS_WORKDIR or PANTS_GLOBAL_PANTS_WORKDIR. We take the first specified value we
      # find, in this order: PANTS_GLOBAL_FOO, PANTS_FOO, FOO.
      env_vars = ['PANTS_GLOBAL_{0}'.format(udest), 'PANTS_{0}'.format(udest)]
      if udest.startswith('PANTS_'):
        env_vars.append(udest)
    else:
      sanitized_env_var_scope = self._ENV_SANITIZER_RE.sub('_', self._scope.upper())
      env_vars = ['PANTS_{0}_{1}'.format(sanitized_env_var_scope, udest)]

    env_val_or_str = None
    env_details = None
    if self._env:
      for env_var in env_vars:
        if env_var in self._env:
          env_val_or_str = expand(self._env.get(env_var))
          env_details = 'from env var {}'.format(env_var)
          break

    # Get value from cmd-line flags.
    flag_vals = [to_value_type(expand(x)) for x in flag_val_strs]
    if is_list_option(kwargs):
      # Note: It's important to set flag_val to None if no flags were specified, so we can
      # distinguish between no flags set vs. explicit setting of the value to [].
      flag_val = ListValueComponent.merge(flag_vals) if flag_vals else None
    elif is_dict_option(kwargs):
      # Note: It's important to set flag_val to None if no flags were specified, so we can
      # distinguish between no flags set vs. explicit setting of the value to {}.
      flag_val = DictValueComponent.merge(flag_vals) if flag_vals else None
    elif len(flag_vals) > 1:
      raise ParseError('Multiple cmd line flags specified for option {} in {}'.format(
          dest, self._scope_str()))
    elif len(flag_vals) == 1:
      flag_val = flag_vals[0]
    else:
      flag_val = None

    # Rank all available values.
    # Note that some of these values may already be of the value type, but type conversion
#.........這裏部分代碼省略.........

  def _compute_default(self, dest, kwargs):
    """Compute the default value to use for an option's registration.

    The source of the default value is chosen according to the ranking in RankedValue.
    """
    is_fromfile = kwargs.get('fromfile', False)
    action = kwargs.get('action')
    if is_fromfile and action:
      raise ParseError('Cannot fromfile {} with an action ({}) in scope {}'
                       .format(dest, action, self._scope))

    config_section = 'DEFAULT' if self._scope == GLOBAL_SCOPE else self._scope
    udest = dest.upper()
    if self._scope == GLOBAL_SCOPE:
      # For convenience, we allow three forms of env var for global scope options.
      # The fully-specified env var is PANTS_DEFAULT_FOO, which is uniform with PANTS_<SCOPE>_FOO
      # for all the other scopes.  However we also allow simply PANTS_FOO. And if the option name
      # itself starts with 'pants-' then we also allow simply FOO. E.g., PANTS_WORKDIR instead of
      # PANTS_PANTS_WORKDIR or PANTS_DEFAULT_PANTS_WORKDIR. We take the first specified value we
      # find, in this order: PANTS_DEFAULT_FOO, PANTS_FOO, FOO.
      env_vars = ['PANTS_DEFAULT_{0}'.format(udest), 'PANTS_{0}'.format(udest)]
      if udest.startswith('PANTS_'):
        env_vars.append(udest)
    else:
      sanitized_env_var_scope = self._ENV_SANITIZER_RE.sub('_', config_section.upper())
      env_vars = ['PANTS_{0}_{1}'.format(sanitized_env_var_scope, udest)]

    value_type = self.str_to_bool if is_boolean_flag(kwargs) else kwargs.get('type', str)

    env_val_str = None
    if self._env:
      for env_var in env_vars:
        if env_var in self._env:
          env_val_str = self._env.get(env_var)
          break

    def expand(val_str):
      if is_fromfile and val_str and val_str.startswith('@') and not val_str.startswith('@@'):
        fromfile = val_str[1:]
        try:
          with open(fromfile) as fp:
            return fp.read().strip()
        except IOError as e:
          raise self.FromfileError('Failed to read {} from file {}: {}'.format(dest, fromfile, e))
      else:
        # Support a literal @ for fromfile values via @@.
        return val_str[1:] if is_fromfile and val_str.startswith('@@') else val_str

    if is_fromfile:
      kwargs['type'] = lambda flag_val_str: value_type(expand(flag_val_str))  # Expand flag values.

    env_val = None if env_val_str is None else value_type(expand(env_val_str))  # Expand env values.

    config_val = None
    if action == 'append':
      config_val_strs = self._config.getlist(config_section, dest) if self._config else None
      if config_val_strs is not None:
        config_val = [value_type(config_val_str) for config_val_str in config_val_strs]
      default = []
    else:
      config_val_str = (self._config.get(config_section, dest, default=None)
                        if self._config else None)
      if config_val_str is not None:
        config_val = value_type(expand(config_val_str))  # Expand config values.
      default = None

    hardcoded_val = kwargs.get('default')  # We don't expand hard coded defaults.
    return RankedValue.choose(None, env_val, config_val, hardcoded_val, default)