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MongoDB: Combine data from multiple collections into one..how?
..., reduce;
db.users_comments.remove();
// setup sample data - wouldn't actually use this in production
db.users.remove();
db.comments.remove();
db.users.save({firstName:"Rich",lastName:"S",gender:"M",country:"CA",age:"18"});
db.users.save({firstName:"Rob",lastName:"M",gender:"M",country:"US",age:"25...
Odd behavior when Java converts int to byte?
...+ unsignedByte);
Would print out: "Signed: -1 Unsigned: 255"
What's actually happening here?
We are using bitwise AND to mask all of the extraneous sign bits (the 1's to the left of the least significant 8 bits.)
When an int is converted into a byte, Java chops-off the left-most 24 bits
111111...
How to avoid explicit 'self' in Python?
...s leads to useful properties, such as: you can't add members which accidentally shadow non-members and thereby break code.
One extreme example: you can write a class without any knowledge of what base classes it might have, and always know whether you are accessing a member or not:
class A(some_fu...
Rails 2.3-style plugins and deprecation warnings running task in Heroku
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Yep, I realize that all the warnings came from my Heroku scripts and logs. I'll assume that (a) it's the plugin injections and (b) that the Heroku team will fix this before it becomes an actual problem.
– fearless_fool
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Convert json data to a html table [closed]
...
Thanks all for your replies. I wrote one myself. Please note that this uses jQuery.
Code snippet:
var myList = [
{ "name": "abc", "age": 50 },
{ "age": "25", "hobby": "swimming" },
{ "name": "xyz", "hobby": "programmin...
Count character occurrences in a string in C++
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Small note, but the return type is typically signed. For some reason std::count returns type iterator_traits<InputIt>::difference_type, which for most standard containers is std::ptrdiff_t, not std::size_t.
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How can I implement a tree in Python?
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I came across this answer via Google. This library is really nice. I especially love the ability to use the mixin class to make an tree of any object!
– Rÿck Nöthing
Mar 8 '19 at 1:21
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Best way to do multiple constructors in PHP
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<?php
class Student
{
public function __construct() {
// allocate your stuff
}
public static function withID( $id ) {
$instance = new self();
$instance->loadByID( $id );
return $instance;
}
public static function withRow( array $row ) {
...
What is the difference between join and merge in Pandas?
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pandas.merge() is the underlying function used for all merge/join behavior.
DataFrames provide the pandas.DataFrame.merge() and pandas.DataFrame.join() methods as a convenient way to access the capabilities of pandas.merge(). For example, df1.merge(right=df2, ...) is equiva...
Is there a TRY CATCH command in Bash
... writing a shell script and need to check that a terminal app has been installed. I want to use a TRY/CATCH command to do this unless there is a neater way.
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