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Most efficient way to reverse a numpy array
Believe it or not, after profiling my current code, the repetitive operation of numpy array reversion ate a giant chunk of the running time. What I have right now is the common view-based method:
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How to update column with null value
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Now, let me clarify. Through php I am using PDO and updating through a query.
– jim
Oct 6 '10 at 8:13
1
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Remove columns from dataframe where ALL values are NA
I'm having trouble with a data frame and couldn't really resolve that issue myself:
The dataframe has arbitrary properties as columns and each row represents one data set .
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open() in Python does not create a file if it doesn't exist
What is the best way to open a file as read/write if it exists, or if it does not, then create it and open it as read/write? From what I read, file = open('myfile.dat', 'rw') should do this, right?
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My attempt at value initialization is interpreted as a function declaration, and why doesn't A a(())
...he language.
If you do have an expression within then it is valid. For example:
((0));//compiles
Even simpler put: because (x) is a valid C++ expression, while () is not.
To learn more about how languages are defined, and how compilers work, you should learn about Formal language theory or m...
Recursively list all files in a directory including files in symlink directories
... directories
/dir/dir11 , /dir/dir12 , and /dir/dir13 . I want to list all the files in dir including the ones in dir11 , dir12 and dir13 .
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How to delete a folder with files using Java
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Java isn't able to delete folders with data in it. You have to delete all files before deleting the folder.
Use something like:
String[]entries = index.list();
for(String s: entries){
File currentFile = new File(index.getPath(),s);
currentFile.delete();
}
Then you should be able to ...
Reserved keywords in JavaScript
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I was just reading about this in JavaScript & jQuery: The Missing Manual:
Not all of these reserved words will cause problems in all browsers, but it’s best to steer clear of these names when naming variables.
JavaScript keywords: break, case, catch, continue, de...
How do I manage MongoDB connections in a Node.js web application?
...on, function(err, db) {
if (err) throw err;
p_db = db;
if(cb && typeof(cb) == 'function')
cb(p_db);
});
return MongoPool;
}
MongoPool.initPool = initPool;
function getInstance(cb){
if(!p_db){
initPool(cb)
}
else{
if(cb && typeof(cb) == 'functi...
C++ where to initialize static const
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Anywhere in one compilation unit (usually a .cpp file) would do:
foo.h
class foo {
static const string s; // Can never be initialized here.
static const char* cs; // Same with C strings.
static const int i = 3; // Integral types can be initialized...