大约有 40,000 项符合查询结果（耗时：0.0435秒） [XML]
Pandas every nth row
...simpler solution to the accepted answer that involves directly invoking df.__getitem__.
df = pd.DataFrame('x', index=range(5), columns=list('abc'))
df
a b c
0 x x x
1 x x x
2 x x x
3 x x x
4 x x x
For example, to get every 2 rows, you can do
df[::2]
a b c
0 x x x
...
mysql :: insert into table, data from another table?
...
INSERT INTO action_2_members (campaign_id, mobile, vote, vote_date)
SELECT campaign_id, from_number, received_msg, date_received
FROM `received_txts`
WHERE `campaign_id` = '8'
...
C# Interfaces. Implicit implementation versus Explicit implementation
...ImplementedException();
}
The difference is that implicit implementation allows you to access the interface through the class you created by casting the interface as that class and as the interface itself. Explicit implementation allows you to access the interface only by casting it as the interfa...
javascript scroll event for iPhone/iPad?
... onscroll only after you've stopped scrolling.
The usual way of installing the handler works e.g.
window.addEventListener('scroll', function() { alert("Scrolled"); });
// or
$(window).scroll(function() { alert("Scrolled"); });
// or
window.onscroll = function() { alert("Scrolled"); };
// etc...
John Carmack's Unusual Fast Inverse Square Root (Quake III)
...s derived is something of a mystery.
To quote Gary Tarolli:
Which actually is doing a floating
point computation in integer - it took
a long time to figure out how and why
this works, and I can't remember the
details anymore.
A slightly better constant, developed by an expert mathemat...
How do I grant myself admin access to a local SQL Server instance?
I installed SQL Server 2008 R2 to my local machine. But, I can't create a new database because of rights (or lack of).
6 An...
Determine Whether Two Date Ranges Overlap
...
Proof:
Let ConditionA Mean that DateRange A Completely After DateRange B
_ |---- DateRange A ------|
|---Date Range B -----| _
(True if StartA > EndB)
Let ConditionB Mean that DateRange A is Completely Before DateRange B
|---- DateRange A ...
How to explicitly discard an out argument?
...ublic void PrintXCoordinate(Point p)
{
p.GetCoordinates(out int x, out _); // I only care about x
WriteLine($"{x}");
}
Source: https://blogs.msdn.microsoft.com/dotnet/2017/03/09/new-features-in-c-7-0/
share
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How do I perform a Perl substitution on a string while keeping the original?
...
I was wondering if something like my $new = $_ for $old =~ s/foo/bar; would work?
– Benoit
Apr 30 '14 at 17:11
...
What's the most elegant way to cap a number to a segment? [closed]
...a-library" answer but just in case you're using Lodash you can use .clamp:
_.clamp(yourInput, lowerBound, upperBound);
So that:
_.clamp(22, -10, 10); // => 10
Here is its implementation, taken from Lodash source:
/**
* The base implementation of `_.clamp` which doesn't coerce arguments.
*
* ...