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Invalid default value for 'create_date' timestamp field
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TIMESTAMP has a range of '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC (see doc). The default value must be within that range.
Other odd, related, behavior:
CREATE TABLE tbl1 (
ts TIMESTAMP);
Query OK, 0 rows affected (0....
Histogram Matplotlib
...m collections import Counter
_, bins = np.histogram(data, bins='auto', range=(data.min(), data.max()), density=False)
h = Counter(np.digitize(data,bins) - 1)
weights = np.asarray(list(h.values()))
weights = weights / weights.sum()
values = np.asarray(list(h.keys()))
return w...
Scala Doubles, and Precision
... math.round(x*m) / m
}
}
This is about 10x faster if you're within the range of Long (i.e 18 digits), so you can round at anywhere between 10^18 and 10^-18.
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Counting the number of True Booleans in a Python List
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In [1]: import random
In [2]: x = [random.choice([True, False]) for i in range(100)]
In [3]: %timeit x.count(True)
970 ns ± 41.1 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
In [4]: %timeit sum(x)
1.72 µs ± 161 ns per loop (mean ± std. dev. of 7 runs, 100000 loops each)
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Hex transparency in colors [duplicate]
...n be solved generically by a cross multiplication.
We have a percentage (ranging from 0 to 100 ) and another number (ranging from 0 to 255) then converted to hexadecimal.
100 <==> 255 (FF in hexadecimal)
0 <==> 0 (00 in hexadecimal)
For 1%
1 * 255 / 100 = 2,5
2,5 in hexa is 2 i...
What are carriage return, linefeed, and form feed?
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The FF char may seem strange today (along with the "CTRL-G" bell char) but it had more relevance back when video displays were far less common and hard copy terminals were used as data displays.
– Rick Sarvas
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How can I measure the similarity between two images? [closed]
...use a combining scaling algorithm instead of nearest pixel
scale the color ranges so that the darkest is black and lightest is white
rotate and flip the image so that the lighest color is top left, and then top-right is next darker, bottom-left is next darker (as far as possible of course)
Edit A ...
How would I extract a single file (or changes to a file) from a git stash?
...(see git rev-parse manpage for explanation of rev^! syntax, in "Specifying ranges" section).
Likewise, you can use git checkout to check a single file out of the stash:
$ git checkout stash@{0} -- <filename>
or to save it under another filename:
$ git show stash@{0}:<full filename> ...
What is the best way to tell if a character is a letter or number in Java without using regexes?
...igit, then the best thing to do is to test by comparing with the character ranges 'a' to 'z', 'A' to 'Z' and '0' to '9'.
Note that all ASCII letters / digits are Unicode letters / digits ... but there are many Unicode letters / digits characters that are not ASCII. For example, accented letters, ...
How to convert wstring into string?
... on this for é, which I will soon fix)
And note that code points in the range 0x80 - 0x9F in Win1252 will not work. This includes €, œ, ž, Ÿ, ...
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