大约有 40,000 项符合查询结果（耗时：0.0314秒） [XML]
Should __init__() call the parent class's __init__()?
...
In Python, calling the super-class' __init__ is optional. If you call it, it is then also optional whether to use the super identifier, or whether to explicitly name the super class:
object.__init__(self)
In case of object, calling the super method is not st...
Total memory used by Python process?
...os
import psutil
process = psutil.Process(os.getpid())
print(process.memory_info().rss) # in bytes
On my current Python 2.7 install with psutil 5.6.3, the last line should be
print(process.memory_info()[0])
instead (there was a change in the API).
Note: do pip install psutil if it is not in...
How to calculate a time difference in C++
...
See std::clock() function.
const clock_t begin_time = clock();
// do something
std::cout << float( clock () - begin_time ) / CLOCKS_PER_SEC;
If you want calculate execution time for self ( not for user ), it is better to do this in clock ticks ( not seco...
Python Sets vs Lists
... as lists, except for their immutability.
Iterating
>>> def iter_test(iterable):
... for i in iterable:
... pass
...
>>> from timeit import timeit
>>> timeit(
... "iter_test(iterable)",
... setup="from __main__ import iter_test; iterable = set(range(1...
Determining 32 vs 64 bit in C++
...vironment or not and use that to set my variables.
// Check windows
#if _WIN32 || _WIN64
#if _WIN64
#define ENVIRONMENT64
#else
#define ENVIRONMENT32
#endif
#endif
// Check GCC
#if __GNUC__
#if __x86_64__ || __ppc64__
#define ENVIRONMENT64
#else
#define ENVIRONMENT32
#endif
#endif
Another easi...
Is it intended by the C++ standards committee that in C++11 unordered_map destroys what it inserts?
...lost three days of my life tracking down a very strange bug where unordered_map::insert() destroys the variable you insert. This highly non-obvious behaviour occurs in very recent compilers only: I found that clang 3.2-3.4 and GCC 4.8 are the only compilers to demonstrate this "feature".
...
Microbit 航向/方位信息 · App Inventor 2 中文网
...
Microbit Magnetometer：航向/方位信息
Microbit_Magnetometer 可以配置 BBC micro:bit 的板载磁力计，并通过适当的方法接收一个或多个磁力计样本。
更多链接：
下载 micro:bit 板载磁力计的示例项目。查看 micro:bit 板载磁力...
How to include external Python code to use in other files?
...
You may interesting imp module and magic call __import__.
– Vitold S.
Dec 5 '15 at 23:53
...
What is time_t ultimately a typedef to?
...
The time_t Wikipedia article article sheds some light on this. The bottom line is that the type of time_t is not guaranteed in the C specification.
The time_t datatype is a data type in
the ISO C library defined for storing
s...
Python argparse mutual exclusive group
...
add_mutually_exclusive_group doesn't make an entire group mutually exclusive. It makes options within the group mutually exclusive.
What you're looking for is subcommands. Instead of prog [ -a xxxx | [-b yyy -c zzz]], you'd hav...