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How to use the PI constant in C++
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On some (especially older) platforms (see the comments below) you might need to
#define _USE_MATH_DEFINES
and then include the necessary header file:
#include <math.h>
and the value of pi can be accessed via:
M_PI
In my math....
How can I rename a field for all documents in MongoDB?
...above are: { upsert:false, multi:true }. You need the multi:true to update all your records.
Or you can use the former way:
remap = function (x) {
if (x.additional){
db.foo.update({_id:x._id}, {$set:{"name.last":x.name.additional}, $unset:{"name.additional":1}});
}
}
db.foo.find().forEach...
How to exit from Python without traceback?
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If sys.exit() is called in "main program stuff", the code above throws away the value passed to sys.exit. Notice that sys.exit raises SystemExit and the variable "e" will contain the exit code.
– bstpierre
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How do you debug PHP scripts? [closed]
...r_dump and print at various points to see where your flow goes wrong. When all else fails though and all I have is SSH and vim I still var_dump()/die() to find where the code goes south.
share
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What does 'super' do in Python?
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What's the difference?
SomeBaseClass.__init__(self)
means to call SomeBaseClass's __init__. while
super(Child, self).__init__()
means to call a bound __init__ from the parent class that follows Child in the instance's Method Resolution Order (MRO).
If the instance is a subclass of ...
Regular expression to find URLs within a string
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It's 2017, and unicode domain names are all over the place. \w may not match international symbols (depends on regex engine), the range is needed instead: a-zA-Z0-9\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF.
– Michael Antipin
Aug...
Debugging in Clojure? [closed]
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There's also dotrace, which allows you to look at the inputs and outputs of selected functions.
(use 'clojure.contrib.trace)
(defn fib[n] (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2)))))
(dotrace [fib] (fib 3))
produces the output:
TRACE t4425: (f...
Unable to find a locale path to store translations for file __init__.py
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Actually you can configure where the locale folder is. In your settings.py add:
LOCALE_PATHS = (
PROJECT_ROOT + '/website/locale', )
Then create a folder for each of the languages you want to translate:
mkdir -p website/...
Removing duplicate objects with Underscore for Javascript
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.uniq/.unique accepts a callback
var list = [{a:1,b:5},{a:1,c:5},{a:2},{a:3},{a:4},{a:3},{a:2}];
var uniqueList = _.uniq(list, function(item, key, a) {
return item.a;
});
// uniqueList = [Object {a=1, b=5}, Object {a=2}, Object {a=3}, Object ...
Check if object is file-like in Python
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It is generally not good practice to have checks like this in your code at all unless you have special requirements.
In Python the typing is dynamic, why do you feel need to check whether the object is file like, rather than just usin...