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Django South - table already exists

...ing database and app you can use the south conversion command ./manage.py convert_to_south myapp This has to be applied before you do any changes to what is already in the database. The convert_to_south command only works entirely on the first machine you run it on. Once you’ve committed the ...
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Why do == comparisons with Integer.valueOf(String) give different results for 127 and 128?

...returning an Integer object, which may have its values cached between -128 and 127. This is why the first value returns true - it's cached - and the second value returns false - 128 isn't a cached value, so you're getting two separate Integer instances. It is important to note that you are compari...
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Difference between encoding and encryption

... want to store text on a hard drive, you're going to have to find a way to convert your characters to bits. Alternatively, if all you have is a flash light, you might want to encode your text using Morse. The result is always "readable", provided you know how it's stored. Encryption means you want ...
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Differences in boolean operators: & vs && and | vs ||

I know the rules for && and || but what are & and | ? Please explain these to me with an example. 11 Ans...
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Random float number generation

How do I generate random floats in C++? 14 Answers 14 ...
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'too many values to unpack', iterating over a dict. key=>string, value=>list

... Can't be iterating directly in dictionary. So you can through converting into tuple. first_names = ['foo', 'bar'] last_names = ['gravy', 'snowman'] fields = { 'first_names': first_names, 'last_name': last_names, } tup_field=tuple(fields.items()) for names in fields.i...
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'printf' vs. 'cout' in C++

What is the difference between printf() and cout in C++? 16 Answers 16 ...
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C语言面试那些事儿──一道指针与数组问题 - C/C++ - 清泛网 - 专注C/C++及内核技术

...面试那些事儿──一道指针与数组问题首先看如下代码:int main(int argc, char** argv){ int a[5] = {1,2,3,4,5}; int* ptr = (int*)(&a + 1); ...首先看如下代码: int main(int argc, char** argv) { int a[5] = {1,2,3,4,5}; int* ptr = (int*)(&a + 1); pr...
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How do I copy the contents of one stream to another?

...s the best way to copy the contents of one stream to another? Is there a standard utility method for this? 13 Answers ...
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How to check that an object is empty in PHP?

... all } If SimpleXMLElement is more than one level deep, you can start by converting it to a pure array: $obj = simplexml_load_file($url); // `json_decode(json_encode($obj), TRUE)` can be slow because // you're converting to and from a JSON string. // I don't know another simple way to do a deep c...