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What is the purpose of the word 'self'?
...
But in __init__(self) method, it accepts self, then even without creating the object, how does it refer to itself?
– saurav
Jan 28 '18 at 10:10
...
PHP abstract properties
...cks (say, in the constructor) for the $tablename variable, e.g.:
class Foo_Abstract {
public final function __construct(/*whatever*/) {
if(!isset($this->tablename))
throw new LogicException(get_class($this) . ' must have a $tablename');
}
}
To enforce this for all derived classes...
How do you round to 1 decimal place in Javascript?
...)
You might want to create a function for this:
function roundedToFixed(_float, _digits){
var rounded = Math.pow(10, _digits);
return (Math.round(_float * rounded) / rounded).toFixed(_digits);
}
share
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...
Allowed characters in Linux environment variable names
...EE Std
1003.1-2001 consist solely of uppercase letters, digits, and the '_'
(underscore) from the characters
defined in Portable Character Set and
do not begin with a digit. Other
characters may be permitted by an
implementation; applications shall
tolerate the presence of such names.
...
Extending the User model with custom fields in Django
...o.contrib.auth.models import User
from django.db.models.signals import post_save
class UserProfile(models.Model):
user = models.OneToOneField(User)
#other fields here
def __str__(self):
return "%s's profile" % self.user
def create_user_profile(sender, instance, creat...
Android Studio installation on Windows 7 fails, no JDK found
...
Adding a system variable JDK_HOME with value c:\Program Files\Java\jdk1.7.0_21\ worked for me. The latest Java release can be downloaded here.
Additionally, make sure the variable JAVA_HOME is also set with the above location.
...
What does the slash mean in help() output?
...meters could only be specified in the C API.
It means the key argument to __contains__ can only be passed in by position (range(5).__contains__(3)), not as a keyword argument (range(5).__contains__(key=3)), something you can do with positional arguments in pure-python functions.
Also see the Argum...
What happens to global and static variables in a shared library when it is dynamically linked?
...yntax similar to the function export/import syntax, i.e.:
#ifdef COMPILING_THE_DLL
#define MY_DLL_EXPORT extern "C" __declspec(dllexport)
#else
#define MY_DLL_EXPORT extern "C" __declspec(dllimport)
#endif
MY_DLL_EXPORT int my_global;
When you do that, the global variable is added to the list of...
How to “EXPIRE” the “HSET” child key in redis?
... mentioning:
When having a hash, the structure basically looks like:
hash_top_key
- child_key_1 -> some_value
- child_key_2 -> some_value
...
- child_key_n -> some_value
Since we want to add TTL to the child keys, we can move them to top keys. The main point is that the key now ...
Detecting endianness programmatically in a C++ program
...e warned against by compiler. That's exactly what unions are for !
bool is_big_endian(void)
{
union {
uint32_t i;
char c[4];
} bint = {0x01020304};
return bint.c[0] == 1;
}
The principle is equivalent to the type case as suggested by others, but this is clearer - and...