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Passing variable number of arguments around
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Best way to select random rows PostgreSQL
...1 AS min_id -- minimum id <= current min id
, 5100000 AS id_span -- rounded up. (max_id - min_id + buffer)
)
SELECT *
FROM (
SELECT p.min_id + trunc(random() * p.id_span)::integer AS id
FROM params p
,generate_series(1, 1100) g -- 1000 +...
Maven Install on Mac OS X
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OS X prior to Mavericks (10.9) actually comes with Maven 3 built in.
If you're on OS X Lion, you won't have java installed by default. Just run java by itself and it'll prompt you to install it.
Assuming qualifications are met, run mvn -version ...
How can I generate Unix timestamps?
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@ĽubomírMlích On a SmartOS host (SunOS 5.11 joyent_20171026T003127Z), I've both /usr/bin/date +%s and /usr/xpg4/bin/date +%s` working. Combined with the POSIX.2 recommendation, I think this works on all Solaris too.
– Dereckson
Nov 5 '17 at ...
Python multiprocessing pool.map for multiple arguments
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edited Oct 10 '17 at 16:11
answered Mar 26 '11 at 14:36
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Version number comparison in Python
...mycmp("1", "1") == 0
assert mycmp("2.1", "2.2") < 0
assert mycmp("3.0.4.10", "3.0.4.2") > 0
assert mycmp("4.08", "4.08.01") < 0
assert mycmp("3.2.1.9.8144", "3.2") > 0
assert mycmp("3.2", "3.2.1.9.8144") < 0
assert mycmp("1.2", "2.1") < 0
assert mycmp("2.1", "1.2") > 0
assert my...
Image Greyscale with CSS & re-color on mouse-over?
.../* Firefox 3.5+ */
filter: gray; /* IE6-9 */
-webkit-filter: grayscale(100%); /* Chrome 19+ & Safari 6+ */
}
img.grayscale:hover {
filter: none;
-webkit-filter: grayscale(0%);
}
img.grayscale {
filter: url("data:image/svg+xml;utf8,<svg xmlns=\'http://www.w3.org/2000/svg\'>...
Where is the Keytool application?
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edited Mar 1 '17 at 10:21
Veverke
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answered ...
Converting strings to floats in a DataFrame
...lso series by series
so it won't convert say a complete string column
In [10]: df = DataFrame(dict(A = Series(['1.0','1']), B = Series(['1.0','foo'])))
In [11]: df
Out[11]:
A B
0 1.0 1.0
1 1 foo
In [12]: df.dtypes
Out[12]:
A object
B object
dtype: object
In [13]: df.convert...
How can I use threading in Python?
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Since this question was asked in 2010, there has been real simplification in how to do simple multithreading with Python with map and pool.
The code below comes from an article/blog post that you should definitely check out (no affiliation) - Parallelism in on...