界面上有很多相同元素，通过索引点击对应的元素（如AAP上商品列表中的添加购物车按钮，点击指定商品的添加购物车按钮），可在..\AppiumLibrary\keywords\__element.py文件中添加如下代码：
def click_by_index(self, locator,index):
"""Click element identified by `locator` and `index`.
Key attributes for arbitrary elements are `index` and `name`.
See`introduction` for details about locating elements.
Args:
- ``locator`` - find elements by locator
- ``index`` - click the element with index
"""
self._info("Clicking element '%s'." % locator)
self._element_find(locator, False, True)[int(index)].click()
