大约有 13,906 项符合查询结果（耗时：0.0235秒） [XML]
LINQ Using Max() to select a single row
...Queryable returned from NHibernate and I need to select the row with the maximum value(s) in a couple of fields.
6 Answers...
How to maintain aspect ratio using HTML IMG tag
...ht and width attribute to 64. I need to show any image resolution (e.g. 256x256, 1024x768, 500x400, 205x246, etc.) as 64x64. But by setting the height and width attributes of an img tag to 64, it's not maintaining the aspect ratio, so the image looks distorted.
...
Using {} in a case statement. Why?
...tter how many lines are there in a case statement, all of the lines are executed. Is this just a rule regarding older/newer compilers or there is something behind that?
...
Pandas percentage of total with groupby
... and divide by sum
state_pcts = state_office.groupby(level=0).apply(lambda x:
100 * x / float(x.sum()))
Returns:
sales
state office_id
AZ 2 16.981365
4 19.250033
6 63.768601
...
Can I implement an autonomous `self` member type in C++?
...of Foo:
template <typename...Ts>
class Self;
template <typename X, typename...Ts>
class Self<X,Ts...> : public Ts...
{
protected:
typedef X self;
};
#define WITH_SELF(X) X : public Self<X>
#define WITH_SELF_DERIVED(X,...) X : public Self<X,__VA_ARGS__>
class WIT...
Find first element in a sequence that matches a predicate
...
To find first element in a sequence seq that matches a predicate:
next(x for x in seq if predicate(x))
Or (itertools.ifilter on Python 2):
next(filter(predicate, seq))
It raises StopIteration if there is none.
To return None if there is no such element:
next((x for x in seq if predic...
Split function equivalent in T-SQL?
... set @iStart = 1
while 1=1
begin
set @iPos = charindex( @cDelimiter, @sString, @iStart )
if @iPos = 0
set @iPos = len( @sString )+1
if @iPos - @iStart > 0
insert into @tParts
values ( substring( @sString, @iStart...
What would a “frozen dict” be?
...sh = hash_
return self._hash
It should work great:
>>> x = FrozenDict(a=1, b=2)
>>> y = FrozenDict(a=1, b=2)
>>> x is y
False
>>> x == y
True
>>> x == {'a': 1, 'b': 2}
True
>>> d = {x: 'foo'}
>>> d[y]
'foo'
...
multiple packages in context:component-scan, spring config
How can I add multiple packages in spring-servlet.xml file in context:component-scan element?
8 Answers
...
What is the purpose of setting a key in data.table?
...ta.table and there are many functions which require me to set a key (e.g. X[Y] ). As such, I wish to understand what a key does in order to properly set keys in my data tables.
...