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Understanding slice notation
...
It's pretty simple really:
a[start:stop] # items start through stop-1
a[start:] # items start through the rest of the array
a[:stop] # items from the beginning through stop-1
a[:] # a copy of the whole array
There is also...
Python - Count elements in list [duplicate]
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len(myList) should do it.
len works with all the collections, and strings too.
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MongoDB drop every database
..."dropping db " + db.getName() );
db.dropDatabase();
}
save it to dropall.js and then execute:
mongo dropall.js
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iOS 7 parallax effect in my view controller
... to the orientation of the user’s device. For example, to emulate the parallax effect on the home screen, you can use the subclass UIInterpolationMotionEffect, as explained here and here, just with a few lines of code.
Objective-C:
// Set vertical effect
UIInterpolatingMotionEffect *verticalMoti...
Is there any difference between __DIR__ and dirname(__FILE__) in PHP?
... ; so, no difference on that.
For example, the two following lines :
var_dump(dirname(__FILE__));
var_dump(__DIR__);
Will both give the same output :
string '/home/squale/developpement/tests/temp' (length=37)
But, there are at least two differences :
__DIR__ only exists with PHP >= 5.3...
When should you not use virtual destructors?
...o not declare a virtual destructor for a class? When should you specifically avoid writing one?
12 Answers
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How to check if running in Cygwin, Mac or Linux?
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Usually, uname with its various options will tell you what environment you're running in:
pax> uname -a
CYGWIN_NT-5.1 IBM-L3F3936 1.5.25(0.156/4/2) 2008-06-12 19:34 i686 Cygwin
pax> uname -s
CYGWIN_NT-5.1
And, accordin...
Relative paths in Python
..., you want to do something like this:
import os
dirname = os.path.dirname(__file__)
filename = os.path.join(dirname, 'relative/path/to/file/you/want')
This will give you the absolute path to the file you're looking for. Note that if you're using setuptools, you should probably use its package re...
Why isn't sizeof for a struct equal to the sum of sizeof of each member?
... errors.
Here's an example using typical settings for an x86 processor (all used 32 and 64 bit modes):
struct X
{
short s; /* 2 bytes */
/* 2 padding bytes */
int i; /* 4 bytes */
char c; /* 1 byte */
/* 3 padding bytes */
};
struct Y
{
int i; /* 4...
How to suppress scientific notation when printing float values?
...cify how many digit after the . you wish to display, this depends on how small is the floating number). See this example:
>>> a = -7.1855143557448603e-17
>>> '{:f}'.format(a)
'-0.000000'
as shown above, default is 6 digits! This is not helpful for our case example, so instead we...