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How to sort objects by multiple keys in Python?
Or, practically, how can I sort a list of dictionaries by multiple keys?
8 Answers
8
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Why do we need extern “C”{ #include } in C++?
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C and C++ are superficially similar, but each compiles into a very different set of code. When you include a header file with a C++ compiler, the compiler is expecting C++ code. If, however, it is a C header, then the compiler expects the data cont...
Creating an empty bitmap and drawing though canvas in Android
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This is probably simpler than you're thinking:
int w = WIDTH_PX, h = HEIGHT_PX;
Bitmap.Config conf = Bitmap.Config.ARGB_8888; // see other conf types
Bitmap bmp = Bitmap.createBitmap(w, h, conf); // this creates a MUTABLE bitmap
Canvas canvas = new Canvas(bmp);
// ready to draw on t...
Why is a round-trip conversion via a string not safe for a double?
...ber(value, 17, &number);
DoubleToNumber is pretty simple -- it just calls _ecvt, which is in the C runtime:
void DoubleToNumber(double value, int precision, NUMBER* number)
{
WRAPPER_CONTRACT
_ASSERTE(number != NULL);
number->precision = precision;
if (((FPDOUBLE*)&val...
Convert Python dict into a dataframe
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The error here, is since calling the DataFrame constructor with scalar values (where it expects values to be a list/dict/... i.e. have multiple columns):
pd.DataFrame(d)
ValueError: If using all scalar values, you must must pass an index
You could ...
Understanding Apache's access log
...the client IP)
%l is the identity of the user determined by identd (not usually used since not reliable)
%u is the user name determined by HTTP authentication
%t is the time the request was received.
%r is the request line from the client. ("GET / HTTP/1.0")
%>s is the status code sent from the s...
What is the Scala annotation to ensure a tail recursive function is optimized?
...e to Scala version 2.8.0.RC5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_18).
Type in expressions to have them evaluated.
Type :help for more information.
scala> import scala.annotation.tailrec
import scala.annotation.tailrec
scala> class Tails {
| @tailrec def boom(x: Int): Int = {
...
How can I reset a react component including all transitively reachable state?
I occasionally have react components that are conceptually stateful which I want to reset. The ideal behavior would be equivalent to removing the old component and readding a new, pristine component.
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Difference between filter and filter_by in SQLAlchemy
... filter on users.id. Instead, it will evaluate id == id as True and return all users. You need to use .filter(users.id == id) (as demoed above). I made this mistake earlier today.
– Nico Cernek
Feb 22 '19 at 23:00
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What difference is there between WebClient and HTTPWebRequest classes in .NET?
...FtpWebRequest, depend on your request. Below is an example:
Example:
var _request = (HttpWebRequest)WebRequest.Create("http://stackverflow.com");
var _response = (HttpWebResponse)_request.GetResponse();
WebClient
System.Object
System.MarshalByRefObject
System.ComponentModel....