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Append an object to a list in R in amortized constant time, O(1)?
... 2-element vector named c as is clearly intended!
– j_random_hacker
Dec 5 '11 at 16:45
7
So is th...
Django ManyToMany filter()
...
Just restating what Tomasz said.
There are many examples of FOO__in=... style filters in the many-to-many and many-to-one tests. Here is syntax for your specific problem:
users_in_1zone = User.objects.filter(zones__id=<id1>)
# same thing but using in
users_in_1zone = User.object...
A python class that acts like dict
...
class Mapping(dict):
def __setitem__(self, key, item):
self.__dict__[key] = item
def __getitem__(self, key):
return self.__dict__[key]
def __repr__(self):
return repr(self.__dict__)
def __len__(self):
re...
What is the canonical way to check for errors using the CUDA runtime API?
...on and wrapper macro like this:
#define gpuErrchk(ans) { gpuAssert((ans), __FILE__, __LINE__); }
inline void gpuAssert(cudaError_t code, const char *file, int line, bool abort=true)
{
if (code != cudaSuccess)
{
fprintf(stderr,"GPUassert: %s %s %d\n", cudaGetErrorString(code), file, lin...
CMake: Print out all accessible variables in a script
...
Using the get_cmake_property function, the following loop will print out all CMake variables defined and their values:
get_cmake_property(_variableNames VARIABLES)
list (SORT _variableNames)
foreach (_variableName ${_variableNames})
...
How to get current CPU and RAM usage in Python?
...#!/usr/bin/env python
import psutil
# gives a single float value
psutil.cpu_percent()
# gives an object with many fields
psutil.virtual_memory()
# you can convert that object to a dictionary
dict(psutil.virtual_memory()._asdict())
# you can have the percentage of used RAM
psutil.virtual_memory().pe...
Abstract methods in Python [duplicate]
...mething along these lines, using ABC
import abc
class Shape(object):
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def method_to_implement(self, input):
"""Method documentation"""
return
Also read this good tutorial: http://www.doughellmann.com/PyMOTW/abc/
You can...
Change auto increment starting number?
In MySQL, I have a table, and I want to set the auto_increment value to 5 instead of 1 . Is this possible and what query statement does this?
...
PHP “php://input” vs $_POST
I have been directed to use the method php://input instead of $_POST when interacting with Ajax requests from JQuery. What I do not understand is the benefits of using this vs the global method of $_POST or $_GET .
...
理解Python的 with 语句 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...hat the statement after with has to evaluate an object that responds to an __enter__() as well as an __exit__() function.
这看起来充满魔法，但不仅仅是魔法，Python对with的处理还很聪明。基本思想是with所求值的对象必须有一个__enter__()方法，一个__exit__()...