大约有 43,000 项符合查询结果（耗时：0.0559秒） [XML]
bash assign default value
...=${LONG_VARIABLE_NAME:-hello} , but now bash also tries to execute 'hello' and that gives a command not found. Any way to avoid that? Or will I have to stick to the latter? Can someone give an example where the assign default is actually useful?
...
The thread has exited with code 0 (0x0) with no unhandled exception
... message. You can switch that off by right clicking into the output window and uncheck Thread Exit Messages.
http://msdn.microsoft.com/en-us/library/bs4c1wda.aspx
In addition to program out from your application, the Output window
can display the information about:
Modules the debugg...
jQuery UI accordion that keeps multiple sections open?
...doesn't allow more than
one content panel to be open at the
same time, and it takes a lot of
effort to do that. If you are looking
for a widget that allows more than one
content panel to be open, don't use
this. Usually it can be written with a
few lines of jQuery instead, something
...
Selecting only numeric columns from a data frame
...list-apply functions:
nums <- unlist(lapply(x, is.numeric))
Then standard subsetting
x[ , nums]
## don't use sapply, even though it's less code
## nums <- sapply(x, is.numeric)
For a more idiomatic modern R I'd now recommend
x[ , purrr::map_lgl(x, is.numeric)]
Less codey, less ref...
Add new field to every document in a MongoDB collection
...to add a new_field to all your collection, you have to use empty selector, and set multi flag to true (last param) to update all the documents
db.your_collection.update(
{},
{ $set: {"new_field": 1} },
false,
true
)
EDIT:
In the above example last 2 fields false, true specifies the upser...
Angularjs - display current date
I got a view in angularjs and I'm just trying to display the current date(formatted). I thought something like <span>{{Date.now() | date:'yyyy-MM-dd'}}</span> should display the current date.
...
Javascript “Not a Constructor” Exception while creating objects
...Project is not a constructor
Variable declarations using var are hoisted and thus always evaluated before the rest of the code. So, this can also be causing issues:
function Project(){}
function localTest() {
new Project(1,2,3); // `Project` points to the local variable,
...
What do (lambda) function closures capture?
Recently I started playing around with Python and I came around something peculiar in the way closures work. Consider the following code:
...
Assign pandas dataframe column dtypes
...you have to use the explicit conversions:
pd.to_datetime, pd.to_timedelta and pd.to_numeric
(As mentioned below, no more "magic", convert_objects has been deprecated in 0.17)
df = pd.DataFrame({'x': {0: 'a', 1: 'b'}, 'y': {0: '1', 1: '2'}, 'z': {0: '2018-05-01', 1: '2018-05-02'}})
df.dtypes
x ...
How can I bind to the change event of a textarea in jQuery?
...tarea> . Like typing any characters (deleting,backspace) or mouse click and paste or cut. Is there a jQuery event that can trigger for all those events?
...