大约有 47,000 项符合查询结果（耗时：0.0605秒） [XML]
Determine if variable is defined in Python [duplicate]
...ime? This is not always obvious because (1) the variable could be conditionally set, and (2) the variable could be conditionally deleted. I'm looking for something like defined() in Perl or isset() in PHP or defined? in Ruby.
...
What is in your Mathematica tool bag? [closed]
We all know that Mathematica is great, but it also often lacks critical functionality. What kind of external packages / tools / resources do you use with Mathematica?
...
C/C++ line number
...processor variables :
__func__ : function name (this is part of C99, not all C++ compilers support it)
__DATE__ : a string of form "Mmm dd yyyy"
__TIME__ : a string of form "hh:mm:ss"
Your code will be :
if(!Logical)
printf("Not logical value at line number %d in file %s\n", __LINE__, __FIL...
Mongoose populate after save
I cannot manually or automatically populate the creator field on a newly saved object ... the only way I can find is to re-query for the objects I already have which I would hate to do.
...
Converting between datetime, Timestamp and datetime64
...>> numpy.__version__
'1.6.2' # current version available via pip install numpy
I can reproduce the long value on numpy-1.8.0 installed as:
pip install git+https://github.com/numpy/numpy.git#egg=numpy-dev
The same example:
>>> from datetime import datetime
>>> import num...
Is either GET or POST more secure than the other?
...e would be to pass it using Secure HTTP.
GET or query string posts are really good for information required for either bookmarking a particular item, or for assisting in search engine optimization and indexing items.
POST is good for standard forms used to submit one time data. I wouldn't use G...
Approximate cost to access various caches and main memory?
...xample, check page 22 for some timings & cycles for example).
Additionally, this page has some details on clock cycles etc. The second link served the following numbers:
Core i7 Xeon 5500 Series Data Source Latency (approximate) [Pg. 22]
local L1 CACHE hit, ...
JavaScript: What are .extend and .prototype used for?
...ate ).lol() // alert message
In the snippet above, I define a method for all Date objects ( already existing ones and all new ones ).
extend is usually a high level function that copies the prototype of a new subclass that you want to extend from the base class.
So you can do something like:
e...
How to include package data with setuptools/distribute?
When using setuptools/distribute, I can not get the installer to pull in any package_data files. Everything I've read says that the following is the correct way to do it. Can someone please advise?
...
What is the preferred/idiomatic way to insert into a map?
...
First of all, operator[] and insert member functions are not functionally equivalent :
The operator[] will search for the key, insert a default constructed value if not found, and return a reference to which you assign a value. Obvi...