大约有 40,000 项符合查询结果（耗时：0.0509秒） [XML]
Why is require_once so bad to use?
...system keeps a log of what's already been included/required. Every *_once call means checking that log. So there's definitely some extra work being done there but enough to detriment the speed of the whole app?
... I really doubt it... Not unless you're on really old hardware or doing it a lot.
I...
Replace all non Alpha Numeric characters, New Lines, and multiple White Space with one Space
...
I marked this answer correct after all these years, because i looked back and the accepted didn't exclude underscores
– Michael Randall
Apr 12 '18 at 11:23
...
How do I base64 encode (decode) in C?
... *output_length = 4 * ((input_length + 2) / 3);
char *encoded_data = malloc(*output_length);
if (encoded_data == NULL) return NULL;
for (int i = 0, j = 0; i < input_length;) {
uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_b = ...
BaseException.message deprecated in Python 2.6
...of the exception hierarchy.
Provides an 'args' attribute that contains all arguments passed
to the constructor. Suggested practice, though, is that only a
single string argument be passed to the constructor."""
__str__ and __repr__ are already implemented in a meaningful way,
especiall...
Bulk insert with SQLAlchemy ORM
...
You also need s.commit() to actually save the records (it took me a bit to figure this one out).
– horcle_buzz
Dec 4 '15 at 1:30
3
...
What is the id( ) function used for?
... Python objects.
Is it the same with memory addresses in C?
Conceptually, yes, in that they are both guaranteed to be unique in their universe during their lifetime. And in one particular implementation of Python, it actually is the memory address of the corresponding C object.
If yes, wh...
Is False == 0 and True == 1 an implementation detail or is it guaranteed by the language?
.....] Boolean values behave like the values 0 and 1, respectively, in almost all contexts, the exception being that when converted to a string, the strings "False" or "True" are returned, respectively.
There is also, for Python 2:
In numeric contexts (for example when used as the argument to an ...
How do exceptions work (behind the scenes) in c++
...
Instead of guessing, I decided to actually look at the generated code with a small piece of C++ code and a somewhat old Linux install.
class MyException
{
public:
MyException() { }
~MyException() { }
};
void my_throwing_function(bool throwit)
{
if (...
Why do people use __(double underscore) so much in C++
...specific, and are slightly more detailed than some others have suggested.
All identifiers that contain a double underscore or start with an underscore followed by an uppercase letter are reserved for the use of the implementation at all scopes, i.e. they might be used for macros.
In addition, all ...
The tilde operator in Python
...a unary operator (taking a single argument) that is borrowed from C, where all data types are just different ways of interpreting bytes. It is the "invert" or "complement" operation, in which all the bits of the input data are reversed.
In Python, for integers, the bits of the twos-complement repr...