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How do I avoid capturing self in blocks when implementing an API?
... If you're not using Automatic Reference Counting (ARC), you can do this:
__block MyDataProcessor *dp = self;
self.progressBlock = ^(CGFloat percentComplete) {
[dp.delegate myAPI:dp isProcessingWithProgress:percentComplete];
}
The __block keyword marks variables that can be modified inside th...
How to properly add cross-site request forgery (CSRF) token using PHP
... deterministically
Try this out:
Generating a CSRF Token
PHP 7
session_start();
if (empty($_SESSION['token'])) {
$_SESSION['token'] = bin2hex(random_bytes(32));
}
$token = $_SESSION['token'];
Sidenote: One of my employer's open source projects is an initiative to backport random_bytes() a...
How to access the ith column of a NumPy multidimensional array?
...0,2]] = something would modify test, and not create another array. But copy_test = test[:, [0,2]] does in fact create a copy as you say.
– Akavall
Apr 11 '14 at 16:19
...
How do I find the location of my Python site-packages directory?
...ysconfig module instead:
python3 -c 'import sysconfig; print(sysconfig.get_paths()["purelib"])'
The per user site-packages directory (PEP 370) is where Python installs your local packages:
python -m site --user-site
If this points to a non-existing directory check the exit status of Python and ...
Nested classes' scope?
...
class Outer(object):
outer_var = 1
class Inner(object):
@property
def inner_var(self):
return Outer.outer_var
This isn't quite the same as similar things work in other languages, and uses global lookup instead of sco...
中文网（自研/维护）拓展 · App Inventor 2 中文网
...nt
Initialize(verticalArrangement)
Method for Initialize
Initialize_Scroll(verticalScrollArrangement)
Method for Initialize_Scroll
RemoveElement(elementIndex)
Method for RemoveElement
Set(list)
Method for Set
SetElement(elementIndex,element)
Method for SetElement
SetEleme...
How to print instances of a class using print()?
...
>>> class Test:
... def __repr__(self):
... return "Test()"
... def __str__(self):
... return "member of Test"
...
>>> t = Test()
>>> t
Test()
>>> print(t)
member of Test
The __str__ method is what h...
Why is “if not someobj:” better than “if someobj == None:” in Python?
...r not ? This is done using the following algorithm :
If the object has a __nonzero__ special method (as do numeric built-ins, int and float), it calls this method. It must either return a bool value which is then directly used, or an int value that is considered False if equal to zero.
Otherwise, ...
How to log a method's execution time exactly in milliseconds?
...
I just compared NSDate and mach_absolute_time() at around 30ms level. 27 vs. 29, 36 vs. 39, 43 vs. 45. NSDate was easier to use for me and the results were similar enough not to bother with mach_absolute_time().
– nevan king
...
Flask-SQLAlchemy import/context issue
...
The flask_sqlalchemy module does not have to be initialized with the app right away - you can do this instead:
# apps.members.models
from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()
class Member(db.Model):
# fields her...