我可以将方法调用存储在元组中而无需在运行时调用方法吗？

Question

此练习称为命令行电子邮件器，它来自自动用python python ch 12 2nd ed。 >

编写一个程序，该程序在 命令行，然后使用硒登录到您的电子邮件帐户 并将字符串的电子邮件发送到提供的地址。 （您可能 想要为此程序设置一个单独的电子邮件帐户。）

在进行此练习时，我了解到硒方法要求查找HTML元素有时会起作用，但是有时它们会扔nosuchelementException。为了解决这个问题，我创建了三个元组来存储硒方法调用。使用selenium_exception_loop（）函数（见下文），我将循环遍历元组，并一次调用一种方法。如果该方法抛出nosuchelementfound异常，则循环将等待两秒钟，然后重试。

当然，问题是在运行时执行硒方法调用。有什么方法可以将硒方法调用存储在集合中，而无需在运行时实际执行呼叫？还是我需要在这里采取完全不同的方法？

#!python3
# 04_command_line_emailer.py -- send emails from the command line
# usage: input four command line arguments:
# sys.argv[1] = email to log into
# sys.argv[2] = password
# sys.argv[3] = email body
# sys.argv[4] = recipient email address


from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.common.exceptions import NoSuchElementException
import sys
import re
import time


class commandLineEmailer:
    def __init__(self):
        self.browser = webdriver.Firefox()
        self.gmail_method_calls = ()
        self.outlook_method_calls = ()
        self.yahoo_method_calls = (
            lambda: self.browser.find_element(By.CLASS_NAME, 'signin').click(),
            lambda: self.browser.find_element(By.NAME, 'username').send_keys(self.return_email_info()[0]),
            lambda: self.browser.find_element(By.NAME, 'signin').click(),
            lambda: self.browser.find_element(By.NAME, 'password').send_keys(sys.argv[2]),
            lambda: self.browser.find_element(By.NAME, 'verifyPassword').click(),
            lambda: self.browser.find_element(By.CSS_SELECTOR, 'Compose').click()
        )

    def return_email_info(self) -> tuple:
        '''
        Input sys.argv[1] into regex. sys.argv[1] contains the sending email
        address. return the username and the email client name.

        :return: tuple, username at index 0, email client name at index 1
        '''
        return re.compile("(.*)(\@)(.*)(\.)").match(sys.argv[1]).group(1), \
               re.compile("(.*)(\@)(.*)(\.)").match(sys.argv[1]).group(3)

    # open browser session and navigate to email client
    def go_to_email_client(self) -> None:
        EMAIL_CLIENTS = {
            'outlook': 'https://www.outlook.com/',
            'gmail': 'https://www.gmail.com/',
            'yahoo': 'https://yahoomail.com/'
        }
        self.browser.get(EMAIL_CLIENTS[self.return_email_info()[1]])

    def selenium_exception_loop(self, selenium_method_collection) -> None:
        '''
        :param selenium_method_collection: input collection containing selenium
         method calls to search for html elements. Wait two seconds between each
         method call. Except the NoSuchElementException error.
        :return: None
        '''
        for selenium_method_call in selenium_method_collection:
            while True:
                try:
                    time.sleep(2) # wait two seconds
                    selenium_method_call()
                    break
                except NoSuchElementException:
                    continue

    def sign_in_and_send(self) -> None:
        '''
        Retrieve the email client to log into. Call the selenium_exception_loop()
        function and pass it the email client tuple containing the selenium
        method calls
        :return None:
        '''
        if self.return_email_info()[1] == 'gmail':
            pass
        elif self.return_email_info()[1] == 'outlook':
            pass
        elif self.return_email_info()[1] == 'yahoo':
            self.selenium_exception_loop(self.yahoo_method_calls)

def main() -> None:
    command_line_emailer = commandLineEmailer()
    command_line_emailer.go_to_email_client()
    command_line_emailer.sign_in_and_send()

if __name__ == "__main__":
    main()

Answer 1

收集了这个答案 lambda 在每个方法调用的前面，然后重写selenium_method AS selenium_method（） ，以便它是可召唤的，就像这样：

yahoo_method_calls = (
    lambda: browser.find_element(By.CLASS_NAME, 'signin').click(),
    lambda: browser.find_element(By.NAME, 'username').send_keys(self.return_email_info()[0]),
)

. . .

try:
    time.sleep(2)  # wait two seconds
    selenium_method_call()  # Call it
    break