code: def normalize_column_name(name):
      
      if not isinstance(name, six.string_types):
          raise ValueError('%r is not a valid column name.' % name)
  
      # limit to 63 characters
      name = name.strip()[:63]
      # column names can be 63 *bytes* max in postgresql
      if isinstance(name, six.text_type):
          while len(name.encode('utf-8')) >= 64:
              name = name[:len(name) - 1]
  
      if not len(name) or '.' in name or '-' in name:
          raise ValueError('%r is not a valid column name.' % name)
      return name
docs: Check if a string is a reasonable thing to use as a column name.