元素定位基本方法
driver.find_element_by_id()
driver.find_element_by_name()
driver.find_element_by_xpath()
driver.find_element_by_class_name()
driver.find_element_by_link_text()
driver.find_element_by_tag_name()
driver.find_element_by_partial_text()
driver.find_element_by_css_selector()

find_element(By.ID," ")
find_element(By.NAME,"")
find_element(By.CLASS_NAME," ")
find_element(By.TAG_NAME," ")
find_element(By.LINK_TEXT," ")
find_element(By.PARTIAL_LINK_TEXT," ")
find_element(By.XPATH," ")
find_element(By.CSS_SELECTOR," ")
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通过子节点找父节点
1. driver.find_element_by_xpath("//*[text()='XXX']/../../")
2. driver.find_element_by_xpath("//*[text()='XXX']/parent::*")
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css 定位，可以用元素的任意属性，只要该属性能唯一标识这个元素。

class 用 '.' 号表示
id 用 ‘#’ 号表示
* 表示所有元素
p 表示所有<p>元素
div > input 选择父节点为<div>的<input>元素
div + input 同级中<div>元素后面的<input>元素
[target=_blank] 表示target=‘_blank’的所有元素