for_statement : statement
                     | COLON inner_statement_list ENDFOR SEMI

def p_for_statement(p):
    '''for_statement : statement
                     | COLON inner_statement_list ENDFOR SEMI'''
    if len(p) == 2:
        p[0] = p[1]
    else:
        p[0] = ast.Block(p[2], lineno=p.lineno(1))