大约有 42,000 项符合查询结果（耗时：0.0530秒） [XML]
What is the purpose of setting a key in data.table?
I am using data.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.
...
Dependency Walker reports IESHIMS.DLL and WER.DLL missing?
...un Dependency Walker on an executable of mine it reports that:
IESHIMS.DLL and WER.DLL can't be found.
4 Answers
...
techniques for obscuring sensitive strings in C++
...
Basically, anyone with access to your program and a debugger can and will find the key in the application if they want to.
But, if you just want to make sure the key doesn't show up when running strings on your binary, you could for instance make sure that the key is no...
How to convert a data frame column to numeric type?
... 3
4 d 4 4 d 4
5 e 5 5 e 5
and let us run:
> sapply(d, mode)
char fake_char fac char_fac num
"character" "character" "numeric" "numeric" "numeric"
> sapply(d, class)
char fake_char fac char...
Best practices for large solutions in Visual Studio (2008) [closed]
...0+ projects, most of them C#. Naturally, it takes a long time to both open and build, so I am looking for best practices for such beasts. Along the lines of questions I am hoping to get answers to, are:
...
Python: Why is functools.partial necessary?
...h lambdas?
Not much in terms of extra functionality (but, see later) – and, readability is in the eye of the beholder.
Most people who are familiar with functional programming languages (those in the Lisp/Scheme families in particular) appear to like lambda just fine – I say "most", definitely...
How to store a dataframe using Pandas
... it back using:
df = pd.read_pickle(file_name)
Note: before 0.11.1 save and load were the only way to do this (they are now deprecated in favor of to_pickle and read_pickle respectively).
Another popular choice is to use HDF5 (pytables) which offers very fast access times for large datasets:
...
How do I find a stored procedure containing ?
...NFORMATION_SCHEMA.ROUTINES
WHERE ROUTINE_DEFINITION LIKE '%Foo%'
AND ROUTINE_TYPE='PROCEDURE'
SELECT OBJECT_NAME(id)
FROM SYSCOMMENTS
WHERE [text] LIKE '%Foo%'
AND OBJECTPROPERTY(id, 'IsProcedure') = 1
GROUP BY OBJECT_NAME(id)
SELECT OBJECT_NAME(object_id)
F...
vim - How to delete a large block of text without counting the lines?
...eleting (or copying) large blocks of text. One can count the lines of text and say (for example) 50dd to delete 50 lines.
...
Is 'float a = 3.0;' a correct statement?
... d = 3; // int
auto e = 3.0; // double
auto f = 3.0f; // float
And similarly, in case of template type deduction :
void foo(float f) { std::cout << "\nfloat"; }
void foo(double d) { std::cout << "\ndouble"; }
template<typename T>
void bar(T t)
{
foo(t);
}
int ...