selenium By八種方式定位元素

              BY方式定位
              使用selenium的By方式定位，首先得導入該模塊
        from selenium.webdriver.common.by import By

1. id屬性定位find_element(By.ID,"id")
2. name屬性定位find_element(By.NAME,"name")
3. classname屬性定位find_element(By.CLASS_NAME,"claname")
4. a標簽文本屬性定位find_element(By.LINK_TEXT,"text")
5. a標簽部分文本屬性定位find_element(By.PARTIAL_LINK_TEXT,"partailtext")
6. 標簽名定位·find_elemnt(By.TAG_NAME,"input")
7. xpath路徑定位find_element(By.XPATH,"//div[@name='name']")
8. css選擇器定位find_element(By.CSS_SELECTOR,"#id")