大约有 40,000 项符合查询结果（耗时：0.0766秒） [XML]
Python Pandas: Get index of rows which column matches certain value
... frame (whose data may be gibabytes). What about dftest? Doesn't this also allocate a very large intermediate object where the returned index may be very small, or even empty. Are these magically optimized away using lazy views. If not then surely there must be an efficient way.
...
What is the difference between sigaction and signal?
...ion() avoids - unless you use the flags explicitly added to sigaction() to allow it to faithfully simulate the old signal() behaviour.
The signal() function does not (necessarily) block other signals from arriving while the current handler is executing; sigaction() can block other signals until the...
Unable to load DLL (Module could not be found HRESULT: 0x8007007E)
...found some dependency's missing (Oracle and some dll from IE). Need to install Oracle since my dll depends on that..then i will know :) Found the problem with DependencyWalker ;)
– Ingimar Andresson
Jan 25 '12 at 13:48
...
How do I check if a string is valid JSON in Python?
...SON.
In general, the "Pythonic" philosophy for this kind of situation is called EAFP, for Easier to Ask for Forgiveness than Permission.
share
|
improve this answer
|
follow...
Cast Int to enum in Java
... 0 or 1, i.e. a valid ordinal for that enum.
Note that in Java enums actually are classes (and enum values thus are objects) and thus you can't cast an int or even Integer to an enum.
share
|
impr...
What's the need of array with zero elements?
...
This is a way to have variable sizes of data, without having to call malloc (kmalloc in this case) twice. You would use it like this:
struct bts_action *var = kmalloc(sizeof(*var) + extra, GFP_KERNEL);
This used to be not standard and was considered a hack (as Aniket said), but it was s...
How to take all but the last element in a sequence using LINQ?
... using generators (yield return).
public static IEnumerable<T> TakeAllButLast<T>(this IEnumerable<T> source) {
var it = source.GetEnumerator();
bool hasRemainingItems = false;
bool isFirst = true;
T item = default(T);
do {
hasRemainingItems = it.MoveN...
Python UTC datetime object's ISO format doesn't include Z (Zulu or Zero offset)
...e objects don't have time zone info by default, and without it, Python actually violates the ISO 8601 specification (if no time zone info is given, assumed to be local time). You can use the pytz package to get some default time zones, or directly subclass tzinfo yourself:
from datetime import date...
How to create a new database after initally installing oracle database 11g Express Edition?
I have installed Oracle Database 11g Express Edition on my pc (windows 7)
and I have installed Oracle SQL Developer as well.
...
“where 1=1” statement [duplicate]
...
It's usually when folks build up SQL statements.
When you add and value = "Toyota" you don't have to worry about whether there is a condition before or just WHERE. The optimiser should ignore it
No magic, just practical
Example ...