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Does C# dictionary store only the reference of the object or the full copy of the object which is added as key?

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问题 I want to use a class as key for a dictionary. But the class is large in terms of memory consumption. So, I want to know that when we add an object as key to dictionary, does it only add its reference or full copy is added. As, if the full copy of the object is added then I can just use the hashcode of the object. 回答1: The dictionary stores whatever value is passed in - that's the case for both the key and the value of the entry. For reference types, that value is a reference - there's no

Creating a dictionary while iterating through multiple for loops?

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问题 I am storing the dates of Presidential speeches and each speech's respective filename in a dictionary. The speeches object looks like this: [<a href="/president/obama/speeches/speech-4427">Acceptance Speech at the Democratic National Convention (August 28, 2008)</a>, <a href="/president/obama/speeches/speech-4424">Remarks on Election Night (November 4, 2008)</a>,...] And end_link looks like: ['/president/obama/speeches/speech-4427', '/president/obama/speeches/speech-4424',...] Here's my code:

parsing text file in tcl and creating dictionary of key value pair where values are in list format

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问题 How to seperate following text file and Keep only require data for corresponding : for example text file have Format: Name Roll_number Subject Experiment_name Marks Result Joy 23 Science Exp related to magnet 45 pass Adi 12 Science Exp electronics 48 pass kumar 18 Maths prime numbers 49 pass Piya 19 Maths number roots 47 pass Ron 28 Maths decimal numbers 12 fail after parsing above Information and storing in dictionary where key is subject(unique) and values corresponding to subject is list

parsing text file in tcl and creating dictionary of key value pair where values are in list format

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Filtering a list of dictionaries based on multiple values

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问题 I have a list of dictionaries that I would like to filter based on multiple criteria. A shortened version of the list looks like so: orders = [{"name": "v", "price": 123, "location": "Mars"}, {"name": "x", "price": 223, "location": "Mars"}, {"name": "x", "price": 124, "location": "Mars"}, {"name": "y", "price": 456, "location": "Mars"}, {"name": "z", "price": 123, "location": "Mars"}, {"name": "z", "price": 5623, "location": "Mars"}] I am looking to end up with a list that contains the

Filtering a list of dictionaries based on multiple values

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How to fix the order of dictionary handling in Python 3?

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问题 Is there a way to reliably fix the order of dictionary handling in Python 3, i.e. establish iteration over keys and values with a predictable order? For debugging purposes and to reproduce a failure that, supposedly, is based on dictionary access in python 3.3 and 3.4, I need to somehow make the iteration over dictionaries predictable. What I mean is I want to fix the way any iteration is performed at the start of the Python program. Such that starting the program many times, calls to dict

C#爬虫实践

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　　忘了什么时候加的，iPad上的人人视频追剧了《我的天才女友》，没事的时候看了下，感觉还不错，进一步了解到原著那不勒斯四部曲，感觉视频进度有些慢，就想找找书看看，一时没找到【PS：购买实体书四十多块钱，虽然目前买得起，但是只是看看故事而不是收藏，不值得买，希望以后有机会补票，而且更习惯使用sp4看pdf或者多看多设备同步阅读进度】，不过找到了在线观看的网站，正好这一段时间有使用C#，就想着使用C#自动将内容抓取下来。断断续续的大概五六个小时的时间，终于功能上实现了。　　由于没怎么研究过爬虫相关知识，不知道是否符合爬虫设计与实践的一些原则，自己做所的不过是通过webrequest抓取页面内容，然后人工分析寻找特征点，找到自己想要的内容。针对这次的任务首先通过目录抓取所有的章节以及对应的页面链接，然后分别抓取每个页面的内容，将章节和内容保存起来。目录中章节链接的提取和每个页面的内容提取都是通过观察尝试实验得到的，不知道是自己哪里设计出了问题，或者就是爬虫本身的特点，感觉很难写出通用的爬虫，很难得到通用的特征点，即使都是在线阅读站点，前端代码不一样，提取的特征都不一样，当前我是直接获取页面内容进行分析，也许会有一些成熟的库，可以直接提取所要的内容。　　不管怎么说，折腾了一场，记录下来，以便以后需要的时候可以查看，而且存储在网络上可以防止丢失。获取页面内容code： /* *

PEP8 multi-line dict with multi-line value

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问题 I use Black for Python, which conforms to PEP8. It removes the indentation from the second line of a two line long value string: mydict = { 'key0': 'value0', 'key1': 'long-two-lines-string-value1-does-not-fit-in-one-line-has-to-continue' 'value1' } to: mydict = { 'key0': 'value0', 'key1': 'long-two-lines-string-value1-does-not-fit-in-one-line-has-to-continue' 'value1', } A colleague questioned this change, and I am wondering if there is any resource/reference that I can use to backup Black's

PEP8 multi-line dict with multi-line value

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