大约有 45,000 项符合查询结果(耗时:0.0580秒) [XML]
Pandas every nth row
...] # Excludes every 3rd row starting from 0
df2 = df[df.index % 3 == 0] # Selects every 3rd raw starting from 0
This arithmetic based sampling has the ability to enable even more complex row-selections.
This assumes, of course, that you have an index column of ordered, consecutive, integers star...
Is gcc std::unordered_map implementation slow? If so - why?
...ith times().
template <typename TEST>
void time_test (TEST t, const char *m) {
struct tms start;
struct tms finish;
long ticks_per_second;
times(&start);
t();
times(&finish);
ticks_per_second = sysconf(_SC_CLK_TCK);
std::cout << "elapsed: "
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Why isn't SQL ANSI-92 standard better adopted over ANSI-89?
...shion. The "best" way to break is by compilation error. For example if you SELECT * somewhere, the addition of a column could fail to compile. The next best way to fail would be a run time error. It's worse because your users may see it, but it still gives you a nice warning that you've broken somet...
How to create a table from select query result in SQL Server 2008 [duplicate]
I want to create a table from select query result in SQL Server, I tried
6 Answers
6
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How to add extra info to copied web text
...cument.location.href}`;
event.clipboardData.setData('text', document.getSelection() + pagelink);
event.preventDefault();
});
Lorem ipsum dolor sit amet, consectetur adipiscing elit.<br/>
<textarea name="textarea" rows="7" cols="50" placeholder="paste your copied text here"></...
Why is  appearing in my HTML? [duplicate]
I see this character in Firebug &#65279; .
10 Answers
10
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How can I generate an MD5 hash?
... “LATIN1” != “ASCII” (or “US-ASCII”). ASCII is a 7-bit character set, Latin1 is an 8-bit character set. They are not the same.
– Bombe
Jan 7 '09 at 7:57
8
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How can I escape a double quote inside double quotes?
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Use a backslash:
echo "\"" # Prints one " character.
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How do I specify a single test in a file with nosetests?
...n both usages should work, as per nose.readthedocs.io/en/latest/usage.html#selecting-tests. Your failure could be caused by tests not being a module in your setup?
– michaeljoseph
Mar 13 '17 at 10:04
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How to send data to local clipboard from a remote SSH session
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I often to this in vim. To do so, select what you want to copy in visual mode, then type: :'<,'>w !ssh desktop pbcopy
– Mike Brennan
Nov 30 '12 at 5:04
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