Generates models from the script input.

def generate_models(args):
  """Generates models from the script input."""
  data_table = get_data_table(args.filename)
  tables = to_tables(data_table.rows_to_dicts())
  attr_indent = "\n" + args.indent * 2
  attr_sep = "," + attr_indent

  for tname, cols in tables.items():
    model_name = table_to_model_name(tname, list(cols.values())[0]["table_schema"])
    pk_cols, oth_cols = split_pks(cols)
    timestamps = get_timestamps(cols, args.created_at_col_name, args.updated_at_col_name)
    is_auto = len(pk_cols) == 1 and cols[pk_cols[0]]["is_auto"] == "t"

    attrs = OrderedDict()
    for cname in oth_cols:
      if cname not in timestamps:
        attrs[cname] = None

    print(_MODEL_SOURCE.format(
      class_name=model_name,
      base_class_name="ModelBase",
      indent=args.indent,
      table_name=repr(tname),
      pk_name=repr(pk_cols[0] if len(pk_cols) == 1 else pk_cols),
      pk_is_auto=is_auto,
      timestamps=timestamps,
      attrs="dict(" + attr_indent + attr_sep.join("{0}={1}".format(k, v) for k, v in attrs.items()) + ")"))
    print()