演示：4种方式定位按钮?

01 / 前言

helium提供方法S实现的是jQuery样式选择器，用于通过ID，名称，CSS识别HTML元素类，CSS选择器或XPath

02 / 入参介绍

以下是源码中的函数介绍:

class S(HTMLElement):  """  :param selector: The selector used to identify the HTML element(s).  A jQuery-style selector for identifying HTML elements by ID, name, CSS  class, CSS selector or XPath. For example: Say you have an element with  ID "myId" on a web page, such as ``<div id="myId" .../>``.  Then you can identify this element using ``S`` as follows::    S("#myId")  The parameter which you pass to ``S(...)`` is interpreted by Helium  according to these rules:   * If it starts with an ``@``, then it identifies elements by HTML ``name``.     Eg. ``S("@btnName")`` identifies an element with ``name="btnName"``.   * If it starts with ``//``, then Helium interprets it as an XPath.   * Otherwise, Helium interprets it as a CSS selector. This in particular     lets you write ``S("#myId")`` to identify an element with ``id="myId"``,     or ``S(".myClass")`` to identify elements with ``class="myClass"``.  ``S`` also makes it possible to read plain text data from a web page. For  example, suppose you have a table of people's email addresses. Then you  can read the list of email addresses as follows::    email_cells = find_all(S("table > tr > td", below="Email"))    emails = [cell.web_element.text for cell in email_cells]  Where ``email`` is the column header (``  ``below`` and ``to_right_of``, the keyword parameters ``above`` and  ``to_left_of`` can be used to search for elements above and to the left  of other web elements.  """  def __init__(self, selector, below=None, to_right_of=None, above=None,      to_left_of=None):    super(S, self).__init__(      below=below, to_right_of=to_right_of, above=above,      to_left_of=to_left_of    )    self._args.append(selector)

参数解释：

:param selector: The selector used to identify the HTML element(s).用于标识HTML元素的选择器。方向参数(在后面文章详细介绍)：below某元素下面to_right_of某元素右边above某元素上面to_left_of某元素左边

03 / 应用场景

场景说明：定位下图中的搜索网页按钮?

"submit" class="b_searchboxSubmit" id="sb_form_go" tabindex="0" name="go">

定位方法如下

代码：

from helium import *class UiWeb():    """公众号：helium自动化测试"""    def __init__(self, url):        self.url = url        self.driver = start_chrome(self.url)if __name__ == '__main__':    test = UiWeb('https://cn.bing.com/')    wait_until(Text('国内版').exists)    s_id = S('#sb_form_go')  # 定位id    highlight(s_id)  # 高亮显示    refresh()    s_name = S('@go')  # 定位name    highlight(s_name)  # 高亮显示    refresh()    s_class = S('.b_searchboxSubmit')  # 定位class    highlight(s_class)  # 高亮显示    refresh()    wait_until(Text('国内版').exists)    s_xpath = S('//*[@id="sb_form_go"]')  # 定位xpath    highlight(s_xpath)