大约有 47,000 项符合查询结果（耗时：0.0199秒） [XML]
How do the likely/unlikely macros in the Linux kernel work and what is their benefit?
I've been digging through some parts of the Linux kernel, and found calls like this:
10 Answers
...
Hidden Features of PHP? [closed]
...and getting a reference most of the time is great.
– Allain Lalonde
Sep 14 '08 at 17:46
1
This is...
uint8_t vs unsigned char
...
It documents your intent - you will be storing small numbers, rather than a character.
Also it looks nicer if you're using other typedefs such as uint16_t or int32_t.
share
|
...
How to shuffle a std::vector?
...n Coliru
Make sure to reuse the same instance of rng throughout multiple calls to std::shuffle if you intend to generate different permutations every time!
Moreover, if you want your program to create different sequences of shuffles each time it is run, you can seed the constructor of the random e...
How to assert output with nosetest/unittest in python?
...rarily replacing sys.stdout. I prefer the context manager because it wraps all the bookkeeping into a single function, so I don't have to re-write any try-finally code, and I don't have to write setup and teardown functions just for this.
import sys
from contextlib import contextmanager
from String...
What is the difference between a mutable and immutable string in C#?
...pe
To "effect a change" on a string represented as a C# String, you actually create a new String object. The original String is not changed ... because it is unchangeable.
In most cases it is better to use String because it is easier reason about them; e.g. you don't need to consider the possib...
What is the proper way to comment functions in Python?
Is there a generally accepted way to comment functions in Python? Is the following acceptable?
10 Answers
...
super() raises “TypeError: must be type, not classobj” for new-style class
...pe(OldStyle()) is the instance type, which does inherit from object. Basically, an old-style class just creates objects of type instance (whereas a new-style class creates objects whose type is the class itself). This is probably why the instance OldStyle() is an object: its type() inherits from ob...
string sanitizer for filename
...a whitelist of characters you are happy to be used? For example, you could allow just good ol' a-z, 0-9, _, and a single instance of a period (.). That's obviously more limiting than most filesystems, but should keep you safe.
...
Principal component analysis in Python
...
Months later, here's a small class PCA, and a picture:
#!/usr/bin/env python
""" a small class for Principal Component Analysis
Usage:
p = PCA( A, fraction=0.90 )
In:
A: an array of e.g. 1000 observations x 20 variables, 1000 rows x 20 colum...