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How do write IF ELSE statement in a MySQL query
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150
You probably want to use a CASE expression.
They look like this:
SELECT col1, col2, (case wh...
Git Extensions: Win32 error 487: Couldn't reserve space for cygwin's heap, Win32 error 0
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14 Answers
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How can I scale the content of an iframe?
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17 Answers
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How many double numbers are there between 0.0 and 1.0?
...or example, that's the number of distinct doubles between 0.5 included and 1.0 excluded, and exactly that many also lie between 1.0 included and 2.0 excluded, and so forth.
Counting the doubles between 0.0 and 1.0 is harder than doing so between powers of two, because there are many powers of two i...
Find the max of two or more columns with pandas
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185
You can get the maximum like this:
>>> import pandas as pd
>>> df = pd.Data...
Sort a list by multiple attributes?
... can be a function that returns a tuple:
s = sorted(s, key = lambda x: (x[1], x[2]))
Or you can achieve the same using itemgetter (which is faster and avoids a Python function call):
import operator
s = sorted(s, key = operator.itemgetter(1, 2))
And notice that here you can use sort instead of...
How to catch integer(0)?
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164
That is R's way of printing a zero length vector (an integer one), so you could test for a bei...
How to map atan2() to degrees 0-360
atan2(y, x) has that discontinuity at 180° where it switches to -180°..0° going clockwise.
15 Answers
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How to count the number of true elements in a NumPy bool array
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>>> import numpy as np
>>> boolarr = np.array([[0, 0, 1], [1, 0, 1], [1, 0, 1]], dtype=np.bool)
>>> boolarr
array([[False, False, True],
[ True, False, True],
[ True, False, True]], dtype=bool)
>>> np.sum(boolarr)
5
Of course, that is a bool...
Why is January month 0 in Java Calendar?
In java.util.Calendar , January is defined as month 0, not month 1. Is there any specific reason to that ?
16 Answers
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