大约有 15,000 项符合查询结果（耗时：0.0286秒） [XML]
DataTrigger where value is NOT null?
...can make a setter that checks to see if a value is NULL and do something. Example:
12 Answers
...
How to reorder data.table columns (without copying)
I'd like to reorder columns in my data.table x , given a character vector of column names, neworder :
2 Answers
...
Rails CSRF Protection + Angular.js: protect_from_forgery makes me to log out on POST
... on your domain could read the cookie, your server can be assured that the XHR came from JavaScript running on your domain.
To take advantage of this (CSRF Protection), your server needs to set a token in a JavaScript readable session
cookie called XSRF-TOKEN on first HTTP GET request. On subsequent...
Set markers for individual points on a line in Matplotlib
...ecify the keyword args linestyle and/or marker in your call to plot.
For example, using a dashed line and blue circle markers:
plt.plot(range(10), linestyle='--', marker='o', color='b')
A shortcut call for the same thing:
plt.plot(range(10), '--bo')
Here is a list of the possible line and ...
Understanding generators in Python
...
Note: this post assumes Python 3.x syntax.†
A generator is simply a function which returns an object on which you can call next, such that for every call it returns some value, until it raises a StopIteration exception, signaling that all values have been...
Assigning code to a variable
... to an Action like this:
var ButtonClicked = new Action(() => MessageBox.Show("hi"));
Then call it:
ButtonClicked();
For completeness (in regards to the various comments)...
As Erik stated, you could execute multiple lines of code:
var ButtonClicked = new Action(() =>
{
MessageBox....
Checking if a string can be converted to float in Python
...
I would just use..
try:
float(element)
except ValueError:
print "Not a float"
..it's simple, and it works
Another option would be a regular expression:
import re
if re.match(r'^-?\d+(?:\.\d+)?$', element) is None:
print "Not float"
...
How to enumerate a range of numbers starting at 1
...parameter so instead you could create two range objects and zip them:
r = xrange(2000, 2005)
r2 = xrange(1, len(r) + 1)
h = zip(r2, r)
print h
Result:
[(1, 2000), (2, 2001), (3, 2002), (4, 2003), (5, 2004)]
If you want to create a generator instead of a list then you can use izip instead.
...
How to insert an item into an array at a specific index (JavaScript)?
...ou want is the splice function on the native array object.
arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert).
In this example we will create an array and add an element to it into index 2:
var arr = [];
arr[0] ...
LINQ: Not Any vs All Don't
...) confusing* when there's an alternative test of equal verbosity and complexity that would return true for the condition we want to act upon. Yet really, I personally find nothing to favour one over the other of the two alternatives you give, and would perhaps lean very slightly toward the former if...