大约有 16,000 项符合查询结果（耗时：0.0497秒） [XML]
Is GridFS fast and reliable enough for production?
I develop a new website and I want to use GridFS as storage for all user uploads, because it offers a lot of advantages compared to a normal filesystem storage.
...
How to group dataframe rows into list in pandas groupby?
...
You can do this using groupby to group on the column of interest and then apply list to every group:
In [1]: df = pd.DataFrame( {'a':['A','A','B','B','B','C'], 'b':[1,2,5,5,4,6]})
df
Out[1]:
a b
0 A 1
1 A 2
2 B 5
3 B 5
4 B 4
5 ...
Good MapReduce examples [closed]
...o count words in a long text with MapReduce" task. I found this wasn't the best example to give others an impression of how powerful this tool can be.
...
What is the advantage to using bloom filters?
I am reading up on bloom filters and they just seem silly. Anything you can accomplish with a bloom filter, you could accomplish in less space, more efficiently, using a single hash function rather than multiple, or that's what it seems. Why would you use a bloom filter and how is it useful?
...
Circular dependency in Spring
How does Spring resolve this: bean A is dependent on bean B, and bean B on bean A.
12 Answers
...
What is the difference between “INNER JOIN” and “OUTER JOIN”?
... with no duplicates, which is a very common case:
An inner join of A and B gives the result of A intersect B, i.e. the inner part of a Venn diagram intersection.
An outer join of A and B gives the results of A union B, i.e. the outer parts of a Venn diagram union.
Examples
Suppose you have two ...
is vs typeof
...
This should answer that question, and then some.
The second line, if (obj.GetType() == typeof(ClassA)) {}, is faster, for those that don't want to read the article.
(Be aware that they don't do the same thing)
share
...
How does `is_base_of` work?
...
If they are related
Let's for a moment assume that B is actually a base of D. Then for the call to check, both versions are viable because Host can be converted to D* and B*. It's a user defined conversion sequence as described by 13.3.3.1.2 from Host<B, D> to D* and B*...
What arguments are passed into AsyncTask?
I don't understand what I am supposed to put in here and where these arguments end up? What exactly should I put, and where exactly will it go? Do I need to include all 3 or can I include 1,2,20?
...
What is the difference between instanceof and Class.isAssignableFrom(…)?
Which of the following is better?
14 Answers
14
...