大约有 14,100 项符合查询结果（耗时：0.0300秒） [XML]
What is Scala's yield?
...on with for and writes a new element into the resulting sequence.
Simple example (from scala-lang)
/** Turn command line arguments to uppercase */
object Main {
def main(args: Array[String]) {
val res = for (a <- args) yield a.toUpperCase
println("Arguments: " + res.toString)
}
}
...
How to pretty-print a numpy.array without scientific notation and with given precision?
...e set_printoptions to set the precision of the output:
import numpy as np
x=np.random.random(10)
print(x)
# [ 0.07837821 0.48002108 0.41274116 0.82993414 0.77610352 0.1023732
# 0.51303098 0.4617183 0.33487207 0.71162095]
np.set_printoptions(precision=3)
print(x)
# [ 0.078 0.48 0.413 ...
What are the sizes used for the iOS application splash screen?
... notice in the dimensions that follow the height takes into account a 20 pixel status bar.
Filename Dimensions
Default-Portrait.png * — 768w x 1024h
Default-PortraitUpsideDown.png — 768w x 1024h
Default-Landscape.png ** — 1024w x 748h
Default-LandscapeLeft.png — 1024w x 748h
Default-Landsca...
Can a C# lambda expression have more than one statement?
Can a C# lambda expression include more than one statement?
8 Answers
8
...
What is more efficient? Using pow to square or just multiply it with itself?
...
I tested the performance difference between x*x*... vs pow(x,i) for small i using this code:
#include <cstdlib>
#include <cmath>
#include <boost/date_time/posix_time/posix_time.hpp>
inline boost::posix_time::ptime now()
{
return boost::posix_tim...
Javascript: Round up to the next multiple of 5
...eger value (ranging from 2 to 5 digits in length) that rounds up to the next multiple of 5 instead of the nearest multiple of 5. Here is what I got:
...
Python: print a generator expression?
...
Quick answer:
Doing list() around a generator expression is (almost) exactly equivalent to having [] brackets around it. So yeah, you can do
>>> list((x for x in string.letters if x in (y for y in "BigMan on campus")))
But you can just as well do
>>>...
Is it possible to have multiple statements in a python lambda expression?
... the second lowest item from a lambda by sorting the list?
A. Yes. As alex's answer points out, sorted() is a version of sort that creates a new list, rather than sorting in-place, and can be chained. Note that this is probably what you should be using - it's bad practice for your map to have sid...
What is the good python3 equivalent for auto tuple unpacking in lambda?
...rder to read than your two suggestions:
min(points, key=lambda p: (lambda x,y: (x*x + y*y))(*p))
update Python 3.8
As of now, Python 3.8 alpha1 is available, and PEP 572- assignment expressions are implemented.
So, if one uses a trick to execute multiple expressions inside a lambda - I usually ...
Is there shorthand for returning a default value if None in Python? [duplicate]
In C#, I can say x ?? "" , which will give me x if x is not null, and the empty string if x is null. I've found it useful for working with databases.
...