text: # coding: utf8
  from __future__ import unicode_literals
  
  from ....symbols import NOUN, VERB, ADJ, PUNCT
  
  
  class GreekLemmatizer(object):
      """
      Greek language lemmatizer applies the default rule based lemmatization
      procedure with some modifications for better Greek language support.
  
      The first modification is that it checks if the word for lemmatization is
      already a lemma and if yes, it just returns it.
      The second modification is about removing the base forms function which is
      not applicable for Greek language.
      """
  
      @classmethod
      def load(cls, path, index=None, exc=None, rules=None, lookup=None):
          return cls(index, exc, rules, lookup)
  
      def __init__(self, index=None, exceptions=None, rules=None, lookup=None):
          self.index = index
          self.exc = exceptions
          self.rules = rules
          self.lookup_table = lookup if lookup is not None else {}
  
      def __call__(self, string, univ_pos, morphology=None):
          if not self.rules:
              return [self.lookup_table.get(string, string)]
          if univ_pos in (NOUN, "NOUN", "noun"):
              univ_pos = "noun"
          elif univ_pos in (VERB, "VERB", "verb"):
              univ_pos = "verb"
          elif univ_pos in (ADJ, "ADJ", "adj"):
              univ_pos = "adj"
          elif univ_pos in (PUNCT, "PUNCT", "punct"):
              univ_pos = "punct"
          else:
              return list(set([string.lower()]))
          lemmas = lemmatize(
              string,
              self.index.get(univ_pos, {}),
              self.exc.get(univ_pos, {}),
              self.rules.get(univ_pos, []),
          )
          return lemmas
  
      def lookup(self, string, orth=None):
          key = orth if orth is not None else string
          if key in self.lookup_table:
              return self.lookup_table[key]
          return string
  
  
  def lemmatize(string, index, exceptions, rules):
      string = string.lower()
      forms = []
      if string in index:
          forms.append(string)
          return forms
      forms.extend(exceptions.get(string, []))
      oov_forms = []
      if not forms:
          for old, new in rules:
              if string.endswith(old):
                  form = string[: len(string) - len(old)] + new
                  if not form:
                      pass
                  elif form in index or not form.isalpha():
                      forms.append(form)
                  else:
                      oov_forms.append(form)
      if not forms:
          forms.extend(oov_forms)
      if not forms:
          forms.append(string)
      return list(set(forms))
  