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python - 循环遍历列表时提前阅读

问题描述

我有一个文本文件列表，如下所示：

page_text_list = ['.............', '.............','name: bill','name: bob','address: 123 main st','name : tim','address: 124' ,'main st','name:', '.......']

如果我在字符串中找到“名称：”，我想提前阅读以获取该名称的地址。但是，正如您所看到的，模式是不一致的，并且并不总是可以假设下一行包含完整地址。

我想使用一个简单的循环遍历列表

for line in page_text_list:

但这似乎不适合这项工作。这里最好的方法是什么？

标签： pythoniterable

解决方案

假设您想要获取该行之后name: ...直到下一name: ...行的所有行的列表，您可以这样做：

from itertools import dropwhile, takewhile

page_text_list = ['.............', '.............','name: bill','name: bob','address: 123 main st','name: tim','address: 124' ,'main st','name:', '.......']

def get_address(name):
    # we drop all the lines who aren't 'name: bob'
    it = dropwhile(lambda line: line != "name: " + name, page_text_list)

    try:
        next(it)  # we drop the 'name: bob' line 
    except StopIteration: # if the name wasn't found, we exhausted the iterator
        pass

    # we return all the following lines, while they don't contain 'name:'
    return list(takewhile(lambda line:"name:" not in line, it))

输出：

print(get_address('bill'))  # no address
# []

print(get_address('dude'))  # not in our list
# []

print('\n'.join(get_address('tim')))
# address: 124
# main st

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