Python EXEC 显示错误：名称未定义

Question

我用 exec 和 selenium 运行如下，

from selenium import webdriver

search_method = 'find_element_by_class_name'

search_word = 'keyword'

exec("elem_search_word = driver." + search_method + "('" + search_word + "')")

elem_search_word.send_keys('python'))

但我出错了，我该怎么办？

elem_search_word.send_keys(str(args.search))

NameError: name 'elem_search_word' is not defined