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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?
...scientific application. One thing I noticed is that GCC will optimize the call pow(a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable ...
第一个Hello,OS World操作系统 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
第一个Hello,OS World操作系统hello_os_word_my_first_os操作系统并非我们想象中的深不可测、遥不可及，只要你对它感兴趣并随我一起动手实践，你也能开发出属于自己的os。本文通过一个最简单的os，完成Hello, OS World文字的输出来演示os...
What are the differences between Perl, Python, AWK and sed? [closed]
...is designed to apply the actions from a script to each line (or, more generally, to specified ranges of lines) of the input file or files. Its language is based on ed, the Unix editor, and although it has conditionals and so on, it is hard to work with for complex tasks. You can work minor miracles ...
Is there a way to 'uniq' by column?
...o you need the ,1 in -k1,1? why not just -k1?
– hello_there_andy
Nov 24 '14 at 20:10
19
@hello_th...
How do I copy an entire directory of files into an existing directory using Python?
...vantage. distutils.errors.DistutilsInternalError: mkpath: 'name' must be a string, i.e. it does not accept PosixPath. Need to str(PosixPath). Wish list for improvement. Other than this matter, I prefer this answer.
– Sun Bear
Aug 27 '19 at 11:59
...
How to make a Python script run like a service or daemon in Linux
...ass the Daemon class and override the run() method
"""
def __init__(self, pidfile, stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):
self.stdin = stdin
self.stdout = stdout
self.stderr = stderr
self.pidfile = p...
ORA-30926: unable to get a stable set of rows in the source tables
...
This is usually caused by duplicates in the query specified in USING clause. This probably means that TABLE_A is a parent table and the same ROWID is returned several times.
You could quickly solve the problem by using a DISTINCT in yo...
What is a semaphore?
...ic static Semaphore Bouncer { get; set; }
public static void Main(string[] args)
{
// Create the semaphore with 3 slots, where 3 are available.
Bouncer = new Semaphore(3, 3);
// Open the nightclub.
OpenNightclub();
}
...
What is a stored procedure?
... a couple of ways. Most major DBMs support stored procedures; however, not all do. You will need to verify with your particular DBMS help documentation for specifics. As I am most familiar with SQL Server I will use that as my samples.
To create a stored procedure the syntax is fairly simple:
CRE...
Remove duplicate dict in list in Python
... {'a': 3222, 'b': 1234},
{'a': 123, 'b': 1234}]
seen = set()
new_l = []
for d in l:
t = tuple(d.items())
if t not in seen:
seen.add(t)
new_l.append(d)
print new_l
Example output:
[{'a': 123, 'b': 1234}, {'a': 3222, 'b': 1234}]
Note: As pointed out by @alexis ...