使用Try和Except语句切换屏幕

Question

我正在为需要在页面中唱歌的web刮板（Selenium和Kivy）制作GUI。有时，它会说要验证您的帐户，理论上，如果selenium驱动程序找到了该页面上的特定元素，它应该切换屏幕（Try和Except）。如果找不到元素，则应添加一条错误消息。但是，这不会切换屏幕，而是停留在第一个屏幕上。我已经对此进行了一段时间的故障排除，我不确定问题出在哪里。当Selenium驱动程序找到元素时，它将运行该try语句中的代码。如果没有，则不会添加错误消息

以下是我的python代码：

import kivy
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.floatlayout import FloatLayout
from kivy.properties import ObjectProperty
from kivy.config import Config
import linkedenInfo
from linkedenInfo import *
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition

Config.set('graphics', 'resizable', True)
Fl = FloatLayout()

#---
class SignInScreen(Screen):
    email = ObjectProperty(None)
    pwd = ObjectProperty(None)

    def sign_in(self):

        user = UsDefined()

        errMsg = Label(text="Incorrect Username or Passoword!\nPlease Try again", size_hint=(.5, 0.05),
                       pos_hint={'top': 0.6, 'center_x': 0.5})
        try:
            user.sign_in(self.email.text, self.pwd.text)
            driver.find_element_by_xpath('//*[@id="global-nav"]')
        except NoSuchElementException:
            try:
                driver.find_element_by_xpath('//*[@id="app__container"]/main/h1')
                LinkedInGui.screen_switch_one(None)

            except NoSuchElementException:
                self.email.text = ""
                self.pwd.text = ""
                Fl.add_widget(errMsg)
#----



class VerifScreen(Screen):
    verifInput = ObjectProperty(None)

class ScreenMang(ScreenManager):
    pass

kv = Builder.load_file("appFormatting.kv")

sm = ScreenManager()
sm.add_widget(VerifScreen(name="_VerifScreen_"))

class LinkedInGui(App):
    def build(self):
        return kv

    def screen_switch_one(self):
        print("Hello 2!")
        sm.current_screen = "_VerifScreen_"



    # run the App


if __name__ == "__main__":
    LinkedInGui().run()

这是我的KV文件：

ScreenMang:
    SignInScreen:
    VerifScreen:


<SignInScreen>
    name: "Sign-In"

    email: userEmail
    pwd: password

    FloatLayout:
        Label:
            text:"LinkedIn Web-Scraper"
            size_hint:(.5, 0.05)
            pos_hint:{'top': 0.975, 'center_x': 0.5}

        TextInput:
            id: userEmail
            hint_text:"LinkedIn Email: "
            size_hint:(.5, 0.05)
            pos_hint:{'center_x': 0.5, 'y': .85}
            multiline:False

        TextInput:
            id: password
            hint_text:"LinkedIn Password: "
            size_hint:(.5, 0.05)
            pos_hint:{'center_x': 0.5, 'y': .8}
            multiline:False
            password:True

        Button:
            text:"Sign-In"
            size_hint:(.5, 0.1)
            pos_hint:{'top': 0.76, 'center_x': .5}
            on_release:
                root.sign_in()


<VerifScreen>
    name: "_VerifScreen_"

    verifInput: verifInput

    FloatLayout:
        Label:
            text: "An SMS text message was sent to your phone number.\nEnter the code below."
            size_hint: (.5, 0.05)
            pos_hint: {'top': 0.79, 'center_x': 0.5}

        TextInput:
            id: verifInput
            hint_text: "Verification Code"
            size_hint: (.5, 0.05)
            pos_hint: {'top': 0.73, 'center_x': 0.5}

        Button:
            text:"Verify"
            size_hint:(.5, 0.1)
            pos_hint:{'top': 0.6, 'center_x': .5}
#            on_release:
#                root.sign_in()

以下是我的Selenium代码：

class UsDefined():

    def sign_in(self, usname, pwd):
        url = 'https://www.linkedin.com/uas/login?session_redirect=https%3A%2F%2Fwww%' \
              '2Elinkedin%2Ecom%2Fsearch%2Fresults%2Fpeople%2F%3Forigin%3DDISCOVER_FROM_' \
              'SEARCH_HOME&fromSignIn=true&trk=cold_join_sign_in'
        driver.get(url)
        driver.find_element_by_id("username").clear()
        driver.find_element_by_id("username").send_keys(usname)
        driver.find_element_by_id("password").clear()
        driver.find_element_by_id("password").send_keys(pwd) 
        driver.find_element_by_id("password").send_keys(Keys.RETURN)

    def verif_code(self, verifNum):
        verifText = driver.find_element_by_xpath('//*[@id="app__container"]/main/h1').text
        driver.find_element_by_xpath('//*[@id="input__phone_verification_pin"]').send_keys(verifNum)
        driver.find_element_by_xpath('//*[@id="input__phone_verification_pin"]').send_keys(Keys.RETURN)

为什么我不能通过python代码切换屏幕？我会在KV文件中编写try和except语句，但这是不可能的

Answer 1

你有没有试过在没有“NosTouchElementException”的情况下运行它

只是一个“例外”：

    try:
        user.sign_in(self.email.text, self.pwd.text)
        driver.find_element_by_xpath('//*[@id="global-nav"]')
    except:
        try:
            driver.find_element_by_xpath('//*[@id="app__container"]/main/h1')
            LinkedInGui.screen_switch_one(None)

        except:
            self.email.text = ""
            self.pwd.text = ""
            Fl.add_widget(errMsg)

这不是最好的方法，但您可以隔离错误