大约有 30,000 项符合查询结果（耗时：0.0596秒） [XML]
How can I efficiently download a large file using Go?
...
I'll assume you mean download via http (error checks omitted for brevity):
import ("net/http"; "io"; "os")
...
out, err := os.Create("output.txt")
defer out.Close()
...
resp, err := http.Get("http://example.com/")
defer resp.Body.Close()
.....
Normalize data in pandas
...0
D 8.892368 0.932785 4.535396 0.598124
In [93]: df_norm = (df - df.mean()) / (df.max() - df.min())
In [94]: df_norm
Out[94]:
a b c d
A 0.085789 -0.394348 0.337016 -0.109935
B -0.463830 0.164926 -0.650963 0.256714
C -0.158129 0.605652 -0.035090 -0.57338...
How to implement a many-to-many relationship in PostgreSQL?
...anguage) statements could look like this:
CREATE TABLE product (
product_id serial PRIMARY KEY -- implicit primary key constraint
, product text NOT NULL
, price numeric NOT NULL DEFAULT 0
);
CREATE TABLE bill (
bill_id serial PRIMARY KEY
, bill text NOT NULL
, billdate date NOT N...
How to update a git clone --mirror?
...
ok, I meant pulling as in the usual parlance. Push and pull technology. There's hardly another word except the nonsensical 'get the data from a remote actively at the client' that would not dub a word that has meaning to git or DVC...
How to get last N records with activerecord?
...last(N)
Example:
User.last(5)
Returns 5 users in descending order by their id.
Deprecated (Old Answer)
An active record query like this I think would get you what you want ('Something' is the model name):
Something.find(:all, :order => "id desc", :limit => 5).reverse
edit: As noted in the com...
What exactly is a reentrant function?
...ned?
Semantically. In this case, this is not a hard-defined term. It just mean "You can do that, without risk".
2. If a program can be safely executed concurrently, does it always mean that it is reentrant?
No.
For example, let's have a C++ function that takes both a lock, and a callback as a pa...
Insert multiple rows WITHOUT repeating the “INSERT INTO …” part of the statement?
...
INSERT INTO dbo.MyTable (ID, Name)
SELECT 123, 'Timmy'
UNION ALL
SELECT 124, 'Jonny'
UNION ALL
SELECT 125, 'Sally'
For SQL Server 2008, can do it in one VALUES clause exactly as per the statement in your question (you just need to add a comma to se...
How do I show the changes which have been staged?
...
It should just be:
git diff --cached
--cached means show the changes in the cache/index (i.e. staged changes) against the current HEAD. --staged is a synonym for --cached.
--staged and --cached does not point to HEAD, just difference with respect to HEAD. If you cherry ...
Can I return the 'id' field after a LINQ insert?
When I enter an object into the DB with Linq-to-SQL can I get the id that I just inserted without making another db call? I am assuming this is pretty easy, I just don't know how.
...
Is there any way to use a numeric type as an object key?
...tring. See Property Accessor docs
Property names must be strings. This means that non-string objects cannot be used as keys in the object. Any non-string object, including a number, is typecasted into a string via the toString method.
> var foo = {}
undefined
> foo[23213] = 'swag'
'swag...