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Coding Practices which enable the compiler/optimizer to make a faster program
...ovide an example of loop unrolling
Before:
unsigned int sum = 0;
for (size_t i; i < BYTES_TO_CHECKSUM; ++i)
{
sum += *buffer++;
}
After unrolling:
unsigned int sum = 0;
size_t i = 0;
**const size_t STATEMENTS_PER_LOOP = 8;**
for (i = 0; i < BYTES_TO_CHECKSUM; **i = i / STATEMENTS_PER_L...
instantiate a class from a variable in PHP?
...you work with namespace, put the current namespace into the string: $var = __NAMESPACE__ . '\\' . $var . 'Class';
– bastey
Sep 2 '13 at 13:28
...
sphinx-build fail - autodoc can't import/find module
..., /docs, ... you might to use sys.path.append(os.path.join(os.path.dirname(__name__), '..')) and then use .. automodule:: app in your .rst-file.
– fnkr
Sep 16 '15 at 9:56
...
PHP check whether property exists in object or class
...
property_exists( mixed $class , string $property )
if (property_exists($ob, 'a'))
isset( mixed $var [, mixed $... ] )
if (isset($ob->a))
isset() will return false if property is null
Example 1:
$ob->a = null
var_du...
Add Foreign Key to existing table
...
To add a foreign key (grade_id) to an existing table (users), follow the following steps:
ALTER TABLE users ADD grade_id SMALLINT UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE users ADD CONSTRAINT fk_grade_id FOREIGN KEY (grade_id) REFERENCES grades(id);
...
How to download image using requests
...flate). You can force it to decompress for you anyway by setting the decode_content attribute to True (requests sets it to False to control decoding itself). You can then use shutil.copyfileobj() to have Python stream the data to a file object:
import requests
import shutil
r = requests.get(settin...
Remove characters except digits from string using Python?
...ion of "everything but" a few characters:
import string
class Del:
def __init__(self, keep=string.digits):
self.comp = dict((ord(c),c) for c in keep)
def __getitem__(self, k):
return self.comp.get(k)
DD = Del()
x='aaa12333bb445bb54b5b52'
x.translate(DD)
also emits '1233344554552'. ...
How can I get the current screen orientation?
...
This only provides two values ORIENTATION_PORTRAIT and ORIENTATION_LANDSCAPE. Is there a way to get all the four values from ActivityInfo? (That is LANDSCAPE_REVERSE and PORTRAIT_REVERSE as well)
– HRJ
May 4 '11 at 9:56
...
Mapping over values in a python dictionary
...ch function; the easiest way to do this is to use a dict comprehension:
my_dictionary = {k: f(v) for k, v in my_dictionary.items()}
In python 2.7, use the .iteritems() method instead of .items() to save memory. The dict comprehension syntax wasn't introduced until python 2.7.
Note that there is ...
How to do what head, tail, more, less, sed do in Powershell? [closed]
...txt | more # or less if you have it installed
gc log.txt | %{ $_ -replace '\d+', '($0)' } # sed
This works well enough for small files, larger ones (more than a few MiB) are probably a bit slow.
The PowerShell Community Extensions include some cmdlets for specialised file stuf...