大约有 30,000 项符合查询结果（耗时：0.1060秒） [XML]
What is a good reason to use SQL views?
...ting the T_NEW table, dropping the T_OLD table and instead creating a VIEW called T_OLD that mimics the T_OLD table 100% (e.g the view query is SELECT all_fields_except_active FROM T_NEW WHERE active=1).
That would allow you to avoid releasing ANY code that currently selects from T_OLD, and do the ...
How to delete items from a dictionary while iterating over it?
...---------------------------------------------------
Traceback (most recent call last):
File "<ipython console>", line 1, in <module>
RuntimeError: dictionary changed size during iteration
As stated in delnan's answer, deleting entries causes problems when the iterator tries to move o...
what is the difference between 'transform' and 'fit_transform' in sklearn
... is meant for when you have already computed PCA, i.e. if you have already called its .fit method.
In [12]: pc2 = RandomizedPCA(n_components=3)
In [13]: pc2.transform(X) # can't transform because it does not know how to do it.
------------------------------------------------------------------------...
How do I find the location of the executable in C? [duplicate]
...the proc symlink points directly to executable.
Note that it is up to the calling process to set argv[0] correctly.
It is right most of the times however there are occasions when the calling process cannot be trusted (ex. setuid executable).
On Windows: use GetModuleFileName(NULL, buf, bufsize)
...
what is faster: in_array or isset? [closed]
...y value until it finds a match.
Being an opcode, it has less overhead than calling the in_array built-in function.
These can be demonstrated by using an array with values (10,000 in the test below), forcing in_array to do more searching.
isset: 0.009623
in_array: 1.738441
This builds on Jaso...
Can I change the viewport meta tag in mobile safari on the fly?
...t.querySelector("meta[name=viewport]");
viewport.setAttribute('content', 'width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0');
Just change the parts you need and Mobile Safari will respect the new settings.
Update:
If you don't already have the meta viewport tag in the so...
difference between iframe, embed and object elements
...m a bird's-eye view, seem to be very similar to the point of being largely identical.
3 Answers
...
How to serve static files in Flask
...xample below, I have moved my templates and static files into a sub-folder called web.
app = Flask(__name__,
static_url_path='',
static_folder='web/static',
template_folder='web/templates')
static_url_path='' removes any preceding path from the URL (i.e.
the ...
How to output something in PowerShell
...e aforementioned value, and being the last item on the command pipeline it calls the .toString() method and outputs the result to STDOUT (by default). A thing of beauty.
The other Write-* commands are specific to outputting the text to their associated streams, and have their place as such.
...
How do you pass custom environment variable on Amazon Elastic Beanstalk (AWS EBS)?
...ng the configuration files. Create a directory at the root of your project called
.ebextensions/
Then create a file called environment.config (this file can be called anything but it must have the .config extension) and add the following values
option_settings:
- option_name: CUSTOM_ENV
va...