Synnefo » snf-ganeti » ganeti-local

import itertools

class _FieldSet(object):

  """A simple field set.

  Among the features are:

    - checking if a string is among a list of static string or regex objects

    - checking if a whole list of string matches

    - returning the matching groups from a regex match

  Internally, all fields are held as regular expression objects.

  """

  def __init__(self, *items):

    self.items = [re.compile("^%s$" % value) for value in items]

  def Extend(self, other_set):

    """Extend the field set with the items from another one"""

    self.items.extend(other_set.items)

  def Matches(self, field):

    """Checks if a field matches the current set

    @type field: str

    @param field: the string to match

    @return: either False or a regular expression match object

    """

    for m in itertools.ifilter(None, (val.match(field) for val in self.items)):

      return m

    return False

  def NonMatching(self, items):

    """Returns the list of fields not matching the current set

    @type items: list

    @param items: the list of fields to check

    @rtype: list

    @return: list of non-matching fields

    """

    return [val for val in items if not self.Matches(val)]