大约有 40,000 项符合查询结果（耗时：0.0353秒） [XML]
Using property() on classmethods
...te the property on the metaclass.
>>> class foo(object):
... _var = 5
... class __metaclass__(type): # Python 2 syntax for metaclasses
... pass
... @classmethod
... def getvar(cls):
... return cls._var
... @classmethod
... def setvar(cls, value):
.....
What's a correct and good way to implement __hash__()?
What's a correct and good way to implement __hash__() ?
6 Answers
6
...
How to rename items in values() in Django?
... could use the extra method:
MyModel.objects.extra(
select={
'renamed_value': 'cryptic_value_name'
}
).values(
'renamed_value'
)
This basically does SELECT cryptic_value_name AS renamed_value in the SQL.
Another option, if you always want the renamed version but the db has the cryptic nam...
How to get POSTed JSON in Flask?
...of all, the .json attribute is a property that delegates to the request.get_json() method, which documents why you see None here.
You need to set the request content type to application/json for the .json property and .get_json() method (with no arguments) to work as either will produce None other...
When to use Comparable and Comparator
... | Comparable | Comparator
._______________________________________________________________________________
Is used to allow Collections.sort to work | yes | yes
Can compare multiple fields | yes ...
How do I check OS with a preprocessor directive?
...ecks. Here are a few of them, with links to where they're found:
Windows
_WIN32 Both 32 bit and 64 bit
_WIN64 64 bit only
Unix (Linux, *BSD, Mac OS X)
See this related question on some of the pitfalls of using this check.
unix
__unix
__unix__
Mac OS X
__APPLE__
__MACH__
Both are de...
Get Root Directory Path of a PHP project
...
For PHP >= 5.3.0 try
PHP magic constants.
__DIR__
And make your path relative.
For PHP < 5.3.0 try
dirname(__FILE__)
share
|
improve this answer
|
...
Best practices for circular shift (rotate) operations in C++
... it to rotate by the width of the type (using fixed-width types like uint32_t).
#include <stdint.h> // for uint32_t
#include <limits.h> // for CHAR_BIT
// #define NDEBUG
#include <assert.h>
static inline uint32_t rotl32 (uint32_t n, unsigned int c)
{
const unsigned int mask...
代码块超过1.2w编译apk报错问题 - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
...ng.api.ApiProxy$RequestTooLargeException: The request to API call datastore_v3.Put() was too large.
at com.google.gwt.user.server.rpc.RPC.encodeResponseForFailure(RPC.java:416)
at com.google.gwt.user.server.rpc.RPC.invokeAnd...
enum - getting value of enum on string conversion
...;>> member.name
'red'
>>> member.value
1
You could add a __str__ method to your enum, if all you wanted was to provide a custom string representation:
class D(Enum):
def __str__(self):
return str(self.value)
x = 1
y = 2
Demo:
>>> from enum import E...