要仅隔离新的过帐，您需要找到某种主键，保证该主键对于每个结果都是唯一的。这可以是url，内部ID等。一旦找到唯一值，就需要在会话之间存储它。对于快速查找的东西，我将使用一组。这是一个基本示例，可以使用集和内置的pickle模块维护您在会话之间看到的结果。

我们将假定您已将结果隔离在列表elements中，并且每个元素都是一个带有<a>标签且具有唯一href值的BeautifulSoup对象。

import os
import pickle

if not os.path.exists('seen.pickle'):  # If the seen file doesnt exist,create it.
    with open('seen.pickle','wb') as file:
        pickle.dump(set(),file)

with open('seen.pickle','rb') as file:  # Load the seen file so we can reference it.
    seen = pickle.load(file)

for element in elements:
    if not element['href'] in seen:
        # Your own code here
        seen.add(element['href'])  # Add it to seen so it is never parsed again

with open('seen.pickle','wb') as file:  # Save the seen file.
    pickle.dump(seen,file)