大约有 900 项符合查询结果（耗时：0.0179秒） [XML]
Improving bulk insert performance in Entity framework [duplicate]
... answered Nov 6 '13 at 12:21
Måns TånnerydMåns Tånneryd
47344 silver badges88 bronze badges
...
What does the Ellipsis object do?
...
In Python 3, you can¹ use the Ellipsis literal ... as a “nop” placeholder for code that hasn't been written yet:
def will_do_something():
...
This is not magic; any expression can be used instead of ..., e.g.:
def will_do_something():
...
How to reset index in a pandas dataframe? [duplicate]
...n that an intermediate result is being cached.
10000 loops, best of 3: 105 µs per loop
In [299]: %timeit df.index = pd.RangeIndex(len(df.index))
The slowest run took 15.05 times longer than the fastest. This could mean that an intermediate result is being cached.
100000 loops, best of 3: 7.84 µs ...
DateTime.ToString(“MM/dd/yyyy HH:mm:ss.fff”) resulted in something like “09/14/2013 07.20.31.371”
... answered Sep 2 '15 at 8:06
Håkon SeljåsenHåkon Seljåsen
46744 silver badges1212 bronze badges
...
How to justify a single flexbox item (override justify-content)
...self, but you can achieve similar result setting appropriate margin to auto¹. E. g. for flex-direction: row (default) you should set margin-right: auto to align the child to the left.
.container {
height: 100px;
border: solid 10px skyblue;
display: flex;
justify-content: flex-e...
In C# check that filename is *possibly* valid (not that it exists) [duplicate]
... edited Apr 30 '17 at 0:51
buræquete
12.5k44 gold badges3131 silver badges6262 bronze badges
answered Jan 7 '09 at 21:11
...
What's the difference between UTF-8 and UTF-8 without BOM?
...ommended but it did wonders to my powershell script when trying to output "æøå"
– Marius
Nov 12 '13 at 9:22
63
...
Numpy: find first index of value fast
...e(100000)
%timeit index(arr, 5) # 1000000 loops, best of 3: 1.88 µs per loop
%timeit find_first(5, arr) # 1000000 loops, best of 3: 1.7 µs per loop
%timeit index(arr, 99999) # 10000 loops, best of 3: 118 µs per loop
%timeit find_first(99999, arr) # 10000 loops, best of 3: 9...
Approximate cost to access various caches and main memory?
... Mutex lock/unlock
100 ns Main memory (RAM)
2 000 ns (2µs) 1KB Zippy-compress
Still some improvements, prediction for 2020
16 000 ns (16µs) SSD random read (olibre's note: should be less)
500 000 ns (½ms) Round trip in datacenter
2 000 000 ns (2ms) HDD random read (s...
Remove rows with duplicate indices (Pandas DataFrame and TimeSeries)
...>> %timeit df3.groupby(df3.index).first()
1000 loops, best of 3: 580 µs per loop
>>> %timeit df3[~df3.index.duplicated(keep='first')]
1000 loops, best of 3: 307 µs per loop
Note that you can keep the last element by changing the keep argument to 'last'.
It should also be noted tha...