无法在硒上找到部分ID

嗨，大家好 ！

我正在尝试查找具有动态ID的元素，但是！无论我做什么，除了系统地引发NoSuchElementException之外...

有我的代码：

try:
    driver.get('http://www.website.com/')
    usr = driver.find_element_by_css_selector("a[id*='txtEmail']")
    pwd = driver.find_element_by_css_selector("a[id*='txtPassword']")

    usr.send_keys(username)
    pwd.send_keys(password)
    driver.find_element_by_css_Selector("a[id*='btnLogin']").click()

    if (driver.find_element_by_css_Selector("a[id$=lnkLogOut]")):
            log.info("Successfully connected")
    else:
            log.error("Login failed - Cannot login to the website - Wrong username/password ?")

    except NoSuchElementException:
            log.error("Cannot find element needed on the login page")

    except TimeoutException:
            log.error("Cannot reach the website in time")
    except:
            log.error("Error occurred during the login attempt: {}".format(sys.exc_info()))

有html形式：

<td>Email/Username:</td>
<td><input name="ctl00$cph1$Login1$txtEmail" id="ctl00_cph1_Login1_txtEmail" style="width:160px;" type="text"></td>

<td>Password:</td>
<td><input name="ctl00$cph1$Login1$txtPassword" id="ctl00_cph1_Login1_txtPassword" style="width:160px;" type="password"></td>
<td><input name="ctl00$cph1$Login1$btnLogin" value="Login" id="ctl00_cph1_Login1_btnLogin" class="fancy" with="80px;" style="height:28px;" type="submit"></td>  

而且有我的输出错误：

DEBUG:selenium.webdriver.remote.remote_connection:POST 

http://127.0.0.1:40943/hub/session {"desiredCapabilities": {"platform": "ANY", "browserName": "firefox", "version": "", "marionette": false, "javascriptEnabled": true}}
DEBUG:selenium.webdriver.remote.remote_connection:Finished Request
DEBUG:selenium.webdriver.remote.remote_connection:POST http://127.0.0.1:40943/hub/session/2b64c16e-1582-42ee-8041-66550781c00f/url {"url": "http://www.website.com", "sessionId": "2b64c16e-1582-42ee-8041-66550781c00f"}
DEBUG:selenium.webdriver.remote.remote_connection:Finished Request
DEBUG:selenium.webdriver.remote.remote_connection:POST http://127.0.0.1:40943/hub/session/2b64c16e-1582-42ee-8041-66550781c00f/element {"using": "css selector", "sessionId": "2b64c16e-1582-42ee-8041-66550781c00f", "value": "a[id*='txtEmail']"}
DEBUG:selenium.webdriver.remote.remote_connection:Finished Request
ERROR:__main__:Cannot find element needed on the login page

问题出在哪里？任何的想法 ？

编辑：以下行会引发错误：

usr = driver.find_element_by_css_selector("a[id*='txtEmail']")
pwd = driver.find_element_by_css_selector("a[id*='txtPassword']")