大约有 48,000 项符合查询结果（耗时：0.0597秒） [XML]
When to use NSInteger vs. int
...amic typedef*s to one of these types, and they are defined like this:
#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
typedef unsigned long NSUInteger;
#else
typedef int NSInteger;
typedef unsigned int NSUInteger;
#endif
Wit...
Generate a heatmap in MatPlotLib using a scatter data set
...
x = y = NP.linspace(-5, 5, 100)
X, Y = NP.meshgrid(x, y)
Z1 = ML.bivariate_normal(X, Y, 2, 2, 0, 0)
Z2 = ML.bivariate_normal(X, Y, 4, 1, 1, 1)
ZD = Z2 - Z1
x = X.ravel()
y = Y.ravel()
z = ZD.ravel()
gridsize=30
PLT.subplot(111)
# if 'bins=None', then color of each hexagon corresponds directly to i...
Should I be using object literals or constructor functions?
...on () {
return this.x + this.y + this.z;
}
};
var ObjCon = function(_x, _y, _z) {
var x = _x; // private
var y = _y; // private
this.z = _z; // public
this.add = function () {
return x + y + this.z; // note x, y doesn't need this.
};
};
// use the objects:
objLit.x = 3;
objLit...
How do I clone a Django model instance object and save it to the database?
...imary key of your object and run save().
obj = Foo.objects.get(pk=<some_existing_pk>)
obj.pk = None
obj.save()
If you want auto-generated key, set the new key to None.
More on UPDATE/INSERT here.
Official docs on copying model instances: https://docs.djangoproject.com/en/2.2/topics/db/que...
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
...
JavaScript: clone a function
...nction.prototype.clone = function() {
var cloneObj = this;
if(this.__isClone) {
cloneObj = this.__clonedFrom;
}
var temp = function() { return cloneObj.apply(this, arguments); };
for(var key in this) {
temp[key] = this[key];
}
temp.__isClone = true;
te...
'id' is a bad variable name in Python
...() is a fundamental built-in:
Help on built-in function id in module
__builtin__:
id(...)
id(object) -> integer
Return the identity of an object. This is guaranteed to be unique among
simultaneously existing objects. (Hint: it's the object's memory
address.)
In g...
How to print to stderr in Python?
...ound this to be the only one short + flexible + portable + readable:
from __future__ import print_function
import sys
def eprint(*args, **kwargs):
print(*args, file=sys.stderr, **kwargs)
The function eprint can be used in the same way as the standard print function:
>>> print("Test...
Check if PHP session has already started
...om a page that doesn't have session started. Therefore when I have session_start() on this script I sometimes get the error message for "session already started". For that I've put these lines:
...
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...