docstr: Return a list of PanLex language varieties.
  
  :param lc: ISO 639 alpha-3 code. If specified, filters returned varieties
      by this code. If unspecified, all varieties are returned.
  :return: the specified language varieties as a list of tuples. The first
      element is the language variety's seven-character uniform identifier,
      and the second element is its default name.
  :rtype: list(tuple)
docstr_tok: ["Return","a","list","of","PanLex","language","varieties",".",":","param","lc",":","ISO","639","alpha-3","code",".","If","specified",",","filters","returned","varieties","by","this","code",".","If","unspecified",",","all","varieties","are","returned",".",":","return",":","the","specified","language","varieties","as","a","list","of","tuples",".","The","first","element","is","the","language","variety","'s","seven-character","uniform","identifier",",","and","the","second","element","is","its","default","name",".",":","rtype",":","list","(","tuple",")"]
code: def language_varieties(self, lc=None):
      """
      Return a list of PanLex language varieties.
  
      :param lc: ISO 639 alpha-3 code. If specified, filters returned varieties
          by this code. If unspecified, all varieties are returned.
      :return: the specified language varieties as a list of tuples. The first
          element is the language variety's seven-character uniform identifier,
          and the second element is its default name.
      :rtype: list(tuple)
      """
  
      if lc is None:
          return self._c.execute(
              "SELECT uid, tt FROM lv ORDER BY uid"
          ).fetchall()
      else:
          return self._c.execute(
              "SELECT uid, tt FROM lv WHERE lc = ? ORDER BY uid", (lc,)
          ).fetchall()
  
file_path: nltk/nltk/corpus/reader/panlex_lite.py
imports: import os
  import sqlite3
  from nltk.corpus.reader.api import CorpusReader
label_desc: Use image node_id 2 for calling the PanLexLiteCorpusReader obj's underlying member method code with example usage: obj.language_varieties(lc) and returns: self, self