大约有 16,000 项符合查询结果（耗时：0.0322秒） [XML]
Why do we need virtual functions in C++?
...
Here is how I understood not just what virtual functions are, but why they're required:
Let's say you have these two classes:
class Animal
{
public:
void eat() { std::cout << "I'm eating generic food."; }
};
class Cat : public Animal
{
public:
void eat()...
How to select rows from a DataFrame based on column values?
How to select rows from a DataFrame based on values in some column in Pandas?
10 Answers
...
Select multiple columns in data.table by their numeric indices
...iple columns using a vector of their numeric indices (position) in data.table ?
5 Answers
...
MSBuild doesn't copy references (DLL files) if using project dependencies in solution
...cts in my Visual Studio solution (everyone targeting .NET 3.5) - for my problem only these two are important:
19 Answers
...
URL Encoding using C#
I have an application which sends a POST request to the VB forum software and logs someone in (without setting cookies or anything).
...
How to invoke the super constructor in Python?
...implicitly. How does one invoke it in Python? I would expect super(self) but this doesn't work.
7 Answers
...
Convert to binary and keep leading zeros in Python
I'm trying to convert an integer to binary using the bin() function in Python. However, it always removes the leading zeros, which I actually need, such that the result is always 8-bit:
...
Understanding the map function
Apply function to every item of iterable and return a list of the results. If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel.
...
How can I convert a dictionary into a list of tuples?
...
>>> d = { 'a': 1, 'b': 2, 'c': 3 }
>>> d.items()
[('a', 1), ('c', 3), ('b', 2)]
>>> [(v, k) for k, v in d.iteritems()]
[(1, 'a'), (3, 'c'), (2, 'b')]
It's not in the order you want, but dicts don't have any specific order an...
Is it good practice to use the xor operator for boolean checks? [closed]
...ke the exclusive or , ^ , operator when it makes sense in the context of boolean checks because of its conciseness. I much prefer to write
...