Can someone explain why some people use this kind of symbols in their code? it's kind of confusing for me and maybe for all the newbies out there.  I am learning Python and I reached a lesson where i should build a web-crawler (spider),in the example they use only how to grab data from a specific url in a specific way i looked in the internet for a general way and found this Code with lot of symbols i know some of them but the rest i have no clue here is a chunk of the code i found with symbols  import sys, thread, Queue, re urllib, urlparse, time, os dupcheck = set() q=Queue.Queue(100) q.put(sys.argv[1]) def queueURLs(html,originalink): for url in re.findall('"'&lt;a[^&gt;]+href["'](.`[^"']+)["']'"', html,re.I):)   what does symbols like this ^> mean in the code  i know that a stand for anchor   and what href stands for but those symbols are confusing
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I don't really understand regular expressions.  Can you explain them to me in an easy-to-follow manner?  If there are any online tools or books, could you also link to them?
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I have the following data:  http://example1.com    anchor text 1     http://example2.com    anchor text 2 http://example3.com    anchor text 3       And I would like the output to be:  http://example1.com    anchor text 1    &lt;a href="http://example1.com"&gt;anchor text 1&lt;/a&gt; http://example2.com    anchor text 2    &lt;a href="http://example1.com"&gt;anchor text 2&lt;/a&gt; http://example3.com    anchor text 3    &lt;a href="http://example1.com"&gt;anchor text 3&lt;/a&gt;   I have tried getting the code to substitute cells A1 and B1 in cell C1 like this:  ="&lt;a href="A1"&gt;B1&lt;/a&gt;"   However, I'm getting errors because of the equal sign and double quotes in the HTML code. I have tried using single quotes to escape it, but still no luck.  Anyone know how to do this? Your help is highly appreciated.
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If I grep a document that contains the following:  ThisExampleString  ...for the expression This*String or *String, nothing is returned. However, This* returns the above line as expected.  Whether the expression is enclosed in quotes makes no difference.  I thought the asterisk indicated any number of unknown characters? Why does it only work if it's at the start of the expression? If this is intended behavior, what do I use instead of the expressions This*String and *String?
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After making it through the major parts of an introductory Lisp book, I still couldn't understand what the special operator (quote) (or equivalent ') function does, yet this has been all over Lisp code that I've seen.    What does it do?
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How can I use/display characters like ♥, ♦, ♣, or ♠ in Java/Eclipse?  When I try to use them directly, e.g. in the source code, Eclipse cannot save the file.  What can I do?  Edit: How can I find the unicode escape sequence?
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I was browsing the html of my favorite site...ahem...and I saw this in the markup:  &lt;link href="/Content/all.min.css?d=20090107" rel="stylesheet" type="text/css" /&gt;   what does "?d=20090107" do? I'm assuming it's a date of some kind, but I'm not sure why it's in the path to the file. Any ideas?
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Some questions, for example    Instead of using a correct URL, such as  http://meta.stackexchange.com/questions/79543/٩●̮̮̃-̃۶-forbid-unicode   are using  https://superuser.com/questions/516363/what-is-the-��-character   What is causing this behavior?
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I'm trying to answer a question, and for that I need to mark 4 different mock (fake) urls and what they'd have. When I type this, a link is automatically created, and I would like to avoid this behaviour since this page doesn't exist. I want to create a link only if I do [] () without space in the middle. Is this even possible? Example of what I mean:    Code for that page   That shouldn't have a link automatically created since it doesn't exist, but inserting it in code is not feasible (because next line is code for that page and there should be a separation). Block quotes didn't work either. I'm asking if this is possible without breaking the url itself, only the hyperlink.
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How to create the following symbol?
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Situation: It started out as me  for the literal string C-c in  but it ended up omitting the - sign and showing results which contained the strings C/C++ and C &amp; C++.  is an example of a post which contains that string of characters (yet fails to show up in the results).  Things I've tried:   post suggests that I can use the undocumented code: operator, but when I do that, it just wraps the whole term in double quotes like .  As @terdon in Unix &amp; Linux chat has , using this  does yield some relevant results, but it doesn't show me  that is supposed to be there. edit: It appears that the Symbolhound query no longer returns that result.  Finally,  says that you can search for literal characters, but as you can see:    Quoted phrases are exact matches except for case-sensitivity, for example, you can search  or .  The second example (symbols) leads to 0 results.  So by now I assume that the search engine has changed (but the old documentation still lingers on this site). Is there a method for me to search for strings that include special (or is it literal?) characters?
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I was reading a book the other day and they distinguished between the usual element symbol (\in) and an element symbol to show that a set is a member of a collection of sets. For the latter they used a square element symbol that looked similar to a wide E. Does anyone know what the code for this might be? The book,says it was prepared with regular LaTeX. Thanks.  The Symbol is
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I saw two less than signs on this Wikipedia article and I was wonder what they meant mathematically.    EDIT: It looks like this can use TeX commands. So I think this is the symbol: $\ll$
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What does double slashes often found in URL's mean exactly?  For example:   http://www.example.com/A/B//C/   Please note that I'm not referring to the beginning right after http:.
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When I type a URL in angle brackets, such as &lt;;, in a comment, the URL is not detected and linked.  Supporting this would allow links to be used more naturally in the flow of text in a comment.  This notation is recommended for embedding URLs in running text by ; quotes are also recommended (I do not know if quotes work or not).
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How rel="next" and rel="prev" helps in SEO, if used for pagination? Is it really required ?  i.e. imagine you're on page 2:  &lt;link rel="prev" href="http://www.example.com/article-part1.html"&gt; &lt;link rel="next" href="http://www.example.com/article-part3.html"&gt;
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I occasionally see the list slice syntax used in Python code like this:  newList = oldList[:]   Surely this is just the same as:  newList = oldList   Or am I missing something?
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Many command-line tools (grep, flex, etc.) use the ^ symbol to denote "beginning of line" and the $ symbol to denote "end of line." When did this convention arise? It seems perfectly reasonable to reserve two characters for these purposes, but it's a bit odd that on modern keyboards the $ symbol is to the left of the ^ symbol.  Is this a completely arbitrary decision? Does this come from some older keyboard layout? Is this convention used because some older tool decided to do things this way?  Regardless of the answer, are there primary sources that document this?