code: def t_INDENTIFIER(t):
      r'(\$?[_a-zA-Z][_a-zA-Z0-9]*)|(__[A-Z_]+__)'
      if t.value in reserved:
          t.type = t.value.upper()
          if t.value in reservedMap:
              t.value = reservedMap[t.value]
      elif t.value in strStatment:
          t.type = 'STATEMENT'
      return f t_INDENTIFIER(t):
      r'(\$?[_a-zA-Z][_a-zA-Z0-9]*)|(__[A-Z_]+__)'
      if t.value in reserved:
          t.type = t.value.upper()
          if t.value in reservedMap:
              t.value = reservedMap[t.value]
      elif t.value in strStatment:
          t.type = 'STATEMENT'
      return t
docs: r'(\$?[_a-zA-Z][_a-zA-Z0-9]*)|(__[A-Z_]+__)